Access Procedures In Wireless Communications

ABSTRACT

Wireless communications for access procedures are described. One or more control messages may indicate a report request associated with an access procedure. One or more reports associated with the access procedure may indicate one or more results associated with one or more access channels.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/790,977, titled “Random Access Report” and filed on Jan. 10, 2019.The above-referenced application is hereby incorporated by reference inits entirety.

BACKGROUND

Wireless communications may use access procedures to establishcommunication between devices. In a random access procedure, acommunication device may send (e.g., transmit) a random access preambleto another communication device, for example, to establish timingsynchronization between the communication devices. A communicationdevice may respond to a random access preamble by sending a randomaccess response. The random access procedure may interfere with anotheraccess procedure that may be initiated by one or more additionalcommunication devices which may lead to undesirable outcomes such asunsuccessful or delayed communications.

SUMMARY

The following summary presents a simplified summary of certain features.The summary is not an extensive overview and is not intended to identifykey or critical elements.

Wireless communications are described. A wireless device may initiate anaccess procedure (e.g., a random access procedure) with a base station,for example, by sending a message (e.g., a random access preamble) tothe base station. The base station may respond, for example, by sendinga report request associated with the access procedure. The reportrequest may indicate at least one channel of a plurality of channels ina cell. The wireless device may respond to the report request, forexample, by sending a message comprising at least one of: an indicationassociated with at least one message (e.g., preamble) transmitted via atleast one channel, and/or an indication associated with at least onemessage transmission attempt associated with the at least one channel.The indication(s) may be used to change one or more access parameters(e.g., random access parameters) of the at least one channel and/or mayavoid/reduce potential collisions between multiple access procedures.

These and other features and advantages are described in greater detailbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

Some features are shown by way of example, and not by limitation, in theaccompanying drawings. In the drawings, like numerals reference similarelements.

FIG. 1 shows an example radio access network (RAN) architecture.

FIG. 2A shows an example user plane protocol stack.

FIG. 2B shows an example control plane protocol stack.

FIG. 3 shows an example wireless device and two base stations.

FIG. 4A, FIG. 4B, FIG. 4C, and FIG. 4D show examples of uplink anddownlink signal transmission.

FIG. 5A shows an example uplink channel mapping and example uplinkphysical signals.

FIG. 5B shows an example downlink channel mapping and example downlinkphysical signals.

FIG. 6 shows an example transmission time and/or reception time for acarrier.

FIG. 7A and FIG. 7B show example sets of orthogonal frequency divisionmultiplexing (OFDM) subcarriers.

FIG. 8 shows example OFDM radio resources.

FIG. 9A shows an example channel state information reference signal(CSI-RS) and/or synchronization signal (SS) block transmission in amulti-beam system.

FIG. 9B shows an example downlink beam management procedure.

FIG. 10 shows an example of configured bandwidth parts (BWPs).

FIG. 11A and FIG. 11B show examples of multi connectivity.

FIG. 12 shows an example of a random access procedure.

FIG. 13 shows example medium access control (MAC) entities.

FIG. 14 shows an example RAN architecture.

FIG. 15 shows example radio resource control (RRC) states.

FIG. 16 shows an example bandwidth part configuration informationelement.

FIG. 17 shows an example serving cell configuration information element.

FIG. 18 shows an example of a coverage of a cell configured with adownlink and two uplinks.

FIG. 19 shows an example of a two-step RA procedure.

FIG. 20 shows an example of contention based and contention-free randomaccess (RA) procedures with LBT.

FIG. 21 shows an example of a two-step RA procedure with LBT.

FIG. 22 shows an example of radio resource allocation for a two-step RAprocedure.

FIG. 23 shows an example of one or more LBT procedures for a two-step RAprocedure.

FIG. 24A and FIG. 24B show examples of one or more LBT procedures for atwo-step RA procedure in an unlicensed band.

FIG. 25 shows an example of one or more PRACH occasion configurations.

FIG. 26 shows an example of one or more PRACH occasion configurations.

FIG. 27A, FIG. 27B, and FIG. 27C show examples of RA response (RAR), aMAC subheader with backoff indicator (BI), and a MAC subheader with arandom access preamble identifier (RAPID), respectively.

FIG. 28 shows an example MAC RAR format.

FIG. 29 shows an example RAR format.

FIG. 30A and FIG. 30B show example RAR formats.

FIG. 31 shows an example of one or more preamble transmissionopportunities.

FIG. 32 shows an example of counter operations.

FIG. 33 shows an example of counter operations.

FIG. 34 shows an example of channel switching.

FIG. 35 shows an example of channel switching.

FIG. 36 shows an example of a random access channel (RACH) informationreport.

FIG. 37 shows an example of a RACH information report.

FIG. 38 shows an example method of a random access operation.

FIG. 39 shows an example method of a random access operation.

FIG. 40 shows example elements of a computing device that may be used toimplement any of the various devices described herein.

DETAILED DESCRIPTION

The accompanying drawings and descriptions provide examples. It is to beunderstood that the examples shown in the drawings and/or described arenon-exclusive and that there are other examples of how features shownand described may be practiced.

Examples are provided for operation of wireless communication systemswhich may be used in the technical field of multicarrier communicationsystems. More particularly, the technology described herein may relateto one or more random access procedures for wireless communications inmulticarrier communication systems.

The following acronyms are used throughout the drawings and/ordescriptions, and are provided below for convenience although otheracronyms may be introduced in the detailed description:

-   3GPP 3rd Generation Partnership Project-   5GC 5G Core Network-   ACK Acknowledgement-   AMF Access and Mobility Management Function-   ARQ Automatic Repeat Request-   AS Access Stratum-   ASIC Application-Specific Integrated Circuit-   BA Bandwidth Adaptation-   BCCH Broadcast Control Channel-   BCH Broadcast Channel-   BFR Beam Failure Recovery-   BLER Block Error Rate-   BPSK Binary Phase Shift Keying-   BSR Buffer Status Report-   BWP Bandwidth Part-   CA Carrier Aggregation-   CC Component Carrier-   CCCH Common Control CHannel-   CDMA Code Division Multiple Access-   CN Core Network-   CORESET Control Resource Set-   CP Cyclic Prefix-   CP-OFDM Cyclic Prefix-Orthogonal Frequency Division Multiplex-   C-RNTI Cell-Radio Network Temporary Identifier-   CS Configured Scheduling-   CSI Channel State Information-   CSI-RS Channel State Information-Reference Signal-   CQI Channel Quality Indicator-   CSS Common Search Space-   CU Central Unit-   DC Dual Connectivity-   DCCH Dedicated Control Channel-   DCI Downlink Control Information-   DL Downlink-   DL-SCH Downlink Shared CHannel-   DM-RS DeModulation Reference Signal-   DRB Data Radio Bearer-   DRX Discontinuous Reception-   DTCH Dedicated Traffic Channel-   DU Distributed Unit-   EPC Evolved Packet Core-   E-UTRA Evolved UMTS Terrestrial Radio Access-   E-UTRAN Evolved-Universal Terrestrial Radio Access Network-   FDD Frequency Division Duplex-   FPGA Field Programmable Gate Arrays-   F1-C F1-Control plane-   F1-U F1-User plane-   gNB next generation Node B-   HARQ Hybrid Automatic Repeat reQuest-   HDL Hardware Description Languages-   IE Information Element-   IP Internet Protocol-   LCH Logical Channel-   LCID Logical Channel Identifier-   LTE Long Term Evolution-   MAC Medium Access Control-   MCG Master Cell Group-   MCS Modulation and Coding Scheme-   MeNB Master evolved Node B-   MIB Master Information Block-   MME Mobility Management Entity-   MN Master Node-   NACK Negative Acknowledgement-   NAS Non-Access Stratum-   NG CP Next Generation Control Plane-   NGC Next Generation Core-   NG-C NG-Control plane-   ng-eNB next generation evolved Node B-   NG-U NG-User plane-   NR New Radio-   NR MAC New Radio MAC-   NR PDCP New Radio PDCP-   NR PHY New Radio PHYsical-   NR RLC New Radio RLC-   NR RRC New Radio RRC-   NSSAI Network Slice Selection Assistance Information-   NUL Normal Uplink-   O&M Operation and Maintenance-   OFDM Orthogonal Frequency Division Multiplexing-   PBCH Physical Broadcast CHannel-   PCC Primary Component Carrier-   PCCH Paging Control CHannel-   PCell Primary Cell-   PCH Paging CHannel-   PDCCH Physical Downlink Control CHannel-   PDCP Packet Data Convergence Protocol-   PDSCH Physical Downlink Shared CHannel-   PDU Protocol Data Unit-   PHICH Physical HARQ Indicator CHannel-   PHY PHYsical-   PLMN Public Land Mobile Network-   PMI Precoding Matrix Indicator-   PRACH Physical Random Access CHannel-   PRB Physical Resource Block-   PSCell Primary Secondary Cell-   PSS Primary Synchronization Signal-   pTAG primary Timing Advance Group-   PT-RS Phase Tracking Reference Signal-   PUCCH Physical Uplink Control CHannel-   PUSCH Physical Uplink Shared CHannel-   QAM Quadrature Amplitude Modulation-   QCLed Quasi-Co-Located-   QCL Quasi-Co-Location-   QFI Quality of Service Indicator-   QoS Quality of Service-   QPSK Quadrature Phase Shift Keying-   RA Random Access-   RACH Random Access CHannel-   RAN Radio Access Network-   RAP Random Access Preamble-   RAT Radio Access Technology-   RA-RNTI Random Access-Radio Network Temporary Identifier-   RB Resource Blocks-   RBG Resource Block Groups-   RI Rank indicator-   RLC Radio Link Control-   RLM Radio Link Monitoring-   RRC Radio Resource Control-   RS Reference Signal-   RSRP Reference Signal Received Power-   SCC Secondary Component Carrier-   SCell Secondary Cell-   SCG Secondary Cell Group-   SC-FDMA Single Carrier-Frequency Division Multiple Access-   SDAP Service Data Adaptation Protocol-   SDU Service Data Unit-   SeNB Secondary evolved Node B-   SFN System Frame Number-   S-GW Serving GateWay-   SI System Information-   SIB System Information Block-   SINR Signal-to-Interference-plus-Noise Ratio-   SMF Session Management Function-   SN Secondary Node-   SpCell Special Cell-   SR Scheduling Request-   SRB Signaling Radio Bearer-   SRS Sounding Reference Signal-   SS Synchronization Signal-   SSB Synchronization Signal Block-   SSS Secondary Synchronization Signal-   sTAG secondary Timing Advance Group-   SUL Supplementary Uplink-   TA Timing Advance-   TAG Timing Advance Group-   TAI Tracking Area Identifier-   TAT Time Alignment Timer-   TB Transport Block-   TC-RNTI Temporary Cell-Radio Network Temporary Identifier-   TCI Transmission Configuration Indication-   TDD Time Division Duplex-   TDMA Time Division Multiple Access-   TRP Transmission and Receiving Point-   TTI Transmission Time Interval-   UCI Uplink Control Information-   UE User Equipment-   UL Uplink-   UL-SCH Uplink Shared CHannel-   UPF User Plane Function-   UPGW User Plane Gateway-   VHDL VHSIC Hardware Description Language-   Xn-C Xn-Control plane-   Xn-U Xn-User plane

Examples described herein may be implemented using various physicallayer modulation and transmission mechanisms. Example transmissionmechanisms may include, but are not limited to: Code Division MultipleAccess (CDMA), Orthogonal Frequency Division Multiple Access (OFDMA),Time Division Multiple Access (TDMA), Wavelet technologies, and/or thelike. Hybrid transmission mechanisms such as TDMA/CDMA, and/or OFDM/CDMAmay be used. Various modulation schemes may be used for signaltransmission in the physical layer. Examples of modulation schemesinclude, but are not limited to: phase, amplitude, code, a combinationof these, and/or the like. An example radio transmission method mayimplement Quadrature Amplitude Modulation (QAM) using Binary Phase ShiftKeying (BPSK), Quadrature Phase Shift Keying (QPSK), 16-QAM, 64-QAM,256-QAM, and/or the like. Physical radio transmission may be enhanced bydynamically or semi-dynamically changing the modulation and codingscheme, for example, depending on transmission requirements and/or radioconditions.

FIG. 1 shows an example Radio Access Network (RAN) architecture. A RANnode may comprise a next generation Node B (gNB) (e.g., 120A, 120B)providing New Radio (NR) user plane and control plane protocolterminations towards a first wireless device (e.g., 110A). A RAN nodemay comprise a base station such as a next generation evolved Node B(ng-eNB) (e.g., 120C, 120D), providing Evolved UMTS Terrestrial RadioAccess (E-UTRA) user plane and control plane protocol terminationstowards a second wireless device (e.g., 110B). A first wireless device110A may communicate with a base station, such as a gNB 120A, over a Uuinterface. A second wireless device 110B may communicate with a basestation, such as an ng-eNB 120D, over a Uu interface. The wirelessdevices 110A and/or 110B may be structurally similar to wireless devicesshown in and/or described in connection with other drawing figures. TheNode B 120A, the Node B 120B, the Node B 120C, and/or the Node B 120Dmay be structurally similar to Nodes B and/or base stations shown inand/or described in connection with other drawing figures.

A base station, such as a gNB (e.g., 120A, 120B, etc.) and/or an ng-eNB(e.g., 120C, 120D, etc.) may host functions such as radio resourcemanagement and scheduling, IP header compression, encryption andintegrity protection of data, selection of Access and MobilityManagement Function (AMF) at wireless device (e.g., User Equipment (UE))attachment, routing of user plane and control plane data, connectionsetup and release, scheduling and transmission of paging messages (e.g.,originated from the AMF), scheduling and transmission of systembroadcast information (e.g., originated from the AMF or Operation andMaintenance (O&M)), measurement and measurement reporting configuration,transport level packet marking in the uplink, session management,support of network slicing, Quality of Service (QoS) flow management andmapping to data radio bearers, support of wireless devices in aninactive state (e.g., RRC_INACTIVE state), distribution function forNon-Access Stratum (NAS) messages, RAN sharing, dual connectivity,and/or tight interworking between NR and E-UTRA.

One or more first base stations (e.g., gNBs 120A and 120B) and/or one ormore second base stations (e.g., ng-eNBs 120C and 120D) may beinterconnected with each other via Xn interface. A first base station(e.g., gNB 120A, 120B, etc.) or a second base station (e.g., ng-eNB120C, 120D, etc.) may be connected via NG interfaces to a network, suchas a 5G Core Network (5GC). A 5GC may comprise one or more AMF/User PlanFunction (UPF) functions (e.g., 130A and/or 130B). A base station (e.g.,a gNB and/or an ng-eNB) may be connected to a UPF via an NG-User plane(NG-U) interface. The NG-U interface may provide delivery (e.g.,non-guaranteed delivery) of user plane Protocol Data Units (PDUs)between a RAN node and the UPF. A base station (e.g., a gNB and/or anng-eNB) may be connected to an AMF via an NG-Control plane (NG-C)interface. The NG-C interface may provide, for example, NG interfacemanagement, wireless device (e.g., UE) context management, wirelessdevice (e.g., UE) mobility management, transport of NAS messages,paging, PDU session management, configuration transfer, and/or warningmessage transmission, combinations thereof, and/or the like.

A UPF may host functions such as anchor point for intra-/inter-RadioAccess Technology (RAT) mobility (e.g., if applicable), external PDUsession point of interconnect to data network, packet routing andforwarding, packet inspection and user plane part of policy ruleenforcement, traffic usage reporting, uplink classifier to supportrouting traffic flows to a data network, branching point to supportmulti-homed PDU session, quality of service (QoS) handling for userplane, packet filtering, gating, Uplink (UL)/Downlink (DL) rateenforcement, uplink traffic verification (e.g., Service Data Flow (SDF)to QoS flow mapping), downlink packet buffering, and/or downlink datanotification triggering.

An AMF may host functions such as NAS signaling termination, NASsignaling security, Access Stratum (AS) security control, inter CoreNetwork (CN) node signaling (e.g., for mobility between 3rd GenerationPartnership Project (3GPP) access networks), idle mode wireless devicereachability (e.g., control and execution of paging retransmission),registration area management, support of intra-system and inter-systemmobility, access authentication, access authorization including check ofroaming rights, mobility management control (e.g., subscription and/orpolicies), support of network slicing, and/or Session ManagementFunction (SMF) selection.

FIG. 2A shows an example user plane protocol stack. A Service DataAdaptation Protocol (SDAP) (e.g., 211 and 221), Packet Data ConvergenceProtocol (PDCP) (e.g., 212 and 222), Radio Link Control (RLC) (e.g., 213and 223), and Medium Access Control (MAC) (e.g., 214 and 224) sublayers,and a Physical (PHY) (e.g., 215 and 225) layer, may be terminated in awireless device (e.g., 110) and in a base station (e.g., 120) on anetwork side. A PHY layer may provide transport services to higherlayers (e.g., MAC, RRC, etc.). Services and/or functions of a MACsublayer may comprise mapping between logical channels and transportchannels, multiplexing and/or demultiplexing of MAC Service Data Units(SDUs) belonging to the same or different logical channels into and/orfrom Transport Blocks (TBs) delivered to and/or from the PHY layer,scheduling information reporting, error correction through HybridAutomatic Repeat request (HARQ) (e.g., one HARQ entity per carrier forCarrier Aggregation (CA)), priority handling between wireless devicessuch as by using dynamic scheduling, priority handling between logicalchannels of a wireless device such as by using logical channelprioritization, and/or padding. A MAC entity may support one or multiplenumerologies and/or transmission timings. Mapping restrictions in alogical channel prioritization may control which numerology and/ortransmission timing a logical channel may use. An RLC sublayer maysupport transparent mode (TM), unacknowledged mode (UM), and/oracknowledged mode (AM) transmission modes. The RLC configuration may beper logical channel with no dependency on numerologies and/orTransmission Time Interval (TTI) durations. Automatic Repeat Request(ARQ) may operate on any of the numerologies and/or TTI durations withwhich the logical channel is configured. Services and functions of thePDCP layer for the user plane may comprise, for example, sequencenumbering, header compression and decompression, transfer of user data,reordering and duplicate detection, PDCP PDU routing (e.g., such as forsplit bearers), retransmission of PDCP SDUs, ciphering, deciphering andintegrity protection, PDCP SDU discard, PDCP re-establishment and datarecovery for RLC AM, and/or duplication of PDCP PDUs. Services and/orfunctions of SDAP may comprise, for example, mapping between a QoS flowand a data radio bearer. Services and/or functions of SDAP may comprisemapping a Quality of Service Indicator (QFI) in DL and UL packets. Aprotocol entity of SDAP may be configured for an individual PDU session.

FIG. 2B shows an example control plane protocol stack. A PDCP (e.g., 233and 242), RLC (e.g., 234 and 243), and MAC (e.g., 235 and 244)sublayers, and a PHY (e.g., 236 and 245) layer, may be terminated in awireless device (e.g., 110), and in a base station (e.g., 120) on anetwork side, and perform service and/or functions described above. RRC(e.g., 232 and 241) may be terminated in a wireless device and a basestation on a network side. Services and/or functions of RRC may comprisebroadcast of system information related to AS and/or NAS; paging (e.g.,initiated by a 5GC or a RAN); establishment, maintenance, and/or releaseof an RRC connection between the wireless device and RAN; securityfunctions such as key management, establishment, configuration,maintenance, and/or release of Signaling Radio Bearers (SRBs) and DataRadio Bearers (DRBs); mobility functions; QoS management functions;wireless device measurement reporting and control of the reporting;detection of and recovery from radio link failure; and/or NAS messagetransfer to/from NAS from/to a wireless device. NAS control protocol(e.g., 231 and 251) may be terminated in the wireless device and AMF(e.g., 130) on a network side. NAS control protocol may performfunctions such as authentication, mobility management between a wirelessdevice and an AMF (e.g., for 3GPP access and non-3GPP access), and/orsession management between a wireless device and an SMF (e.g., for 3GPPaccess and non-3GPP access).

A base station may configure a plurality of logical channels for awireless device. A logical channel of the plurality of logical channelsmay correspond to a radio bearer. The radio bearer may be associatedwith a QoS requirement. A base station may configure a logical channelto be mapped to one or more TTIs and/or numerologies in a plurality ofTTIs and/or numerologies. The wireless device may receive DownlinkControl Information (DCI) via a Physical Downlink Control CHannel(PDCCH) indicating an uplink grant. The uplink grant may be for a firstTTI and/or a first numerology and may indicate uplink resources fortransmission of a TB. The base station may configure each logicalchannel in the plurality of logical channels with one or more parametersto be used by a logical channel prioritization procedure at the MAClayer of the wireless device. The one or more parameters may comprise,for example, priority, prioritized bit rate, etc. A logical channel inthe plurality of logical channels may correspond to one or more bufferscomprising data associated with the logical channel. The logical channelprioritization procedure may allocate the uplink resources to one ormore first logical channels in the plurality of logical channels and/orto one or more MAC Control Elements (CEs). The one or more first logicalchannels may be mapped to the first TTI and/or the first numerology. TheMAC layer at the wireless device may multiplex one or more MAC CEsand/or one or more MAC SDUs (e.g., logical channel) in a MAC PDU (e.g.,TB). The MAC PDU may comprise a MAC header comprising a plurality of MACsub-headers. A MAC sub-header in the plurality of MAC sub-headers maycorrespond to a MAC CE or a MAC SUD (e.g., logical channel) in the oneor more MAC CEs and/or in the one or more MAC SDUs. A MAC CE and/or alogical channel may be configured with a Logical Channel IDentifier(LCID). An LCID for a logical channel and/or a MAC CE may be fixedand/or pre-configured. An LCID for a logical channel and/or MAC CE maybe configured for the wireless device by the base station. The MACsub-header corresponding to a MAC CE and/or a MAC SDU may comprise anLCID associated with the MAC CE and/or the MAC SDU.

A base station may activate, deactivate, and/or impact one or moreprocesses (e.g., set values of one or more parameters of the one or moreprocesses or start and/or stop one or more timers of the one or moreprocesses) at the wireless device, for example, by using one or more MACcommands. The one or more MAC commands may comprise one or more MACcontrol elements. The one or more processes may comprise activationand/or deactivation of PDCP packet duplication for one or more radiobearers. The base station may send (e.g., transmit) a MAC CE comprisingone or more fields. The values of the fields may indicate activationand/or deactivation of PDCP duplication for the one or more radiobearers. The one or more processes may comprise Channel StateInformation (CSI) transmission of on one or more cells. The base stationmay send (e.g., transmit) one or more MAC CEs indicating activationand/or deactivation of the CSI transmission on the one or more cells.The one or more processes may comprise activation and/or deactivation ofone or more secondary cells. The base station may send (e.g., transmit)a MAC CE indicating activation and/or deactivation of one or moresecondary cells. The base station may send (e.g., transmit) one or moreMAC CEs indicating starting and/or stopping of one or more DiscontinuousReception (DRX) timers at the wireless device. The base station may send(e.g., transmit) one or more MAC CEs that indicate one or more timingadvance values for one or more Timing Advance Groups (TAGs).

FIG. 3 shows an example of base stations (base station 1, 120A, and basestation 2, 120B) and a wireless device 110. The wireless device 110 maycomprise a UE or any other wireless device. The base station (e.g.,120A, 120B) may comprise a Node B, eNB, gNB, ng-eNB, or any other basestation. A wireless device and/or a base station may perform one or morefunctions of a relay node. The base station 1, 120A, may comprise atleast one communication interface 320A (e.g., a wireless modem, anantenna, a wired modem, and/or the like), at least one processor 321A,and at least one set of program code instructions 323A that may bestored in non-transitory memory 322A and executable by the at least oneprocessor 321A. The base station 2, 120B, may comprise at least onecommunication interface 320B, at least one processor 321B, and at leastone set of program code instructions 323B that may be stored innon-transitory memory 322B and executable by the at least one processor321B.

A base station may comprise any number of sectors, for example: 1, 2, 3,4, or 6 sectors. A base station may comprise any number of cells, forexample, ranging from 1 to 50 cells or more. A cell may be categorized,for example, as a primary cell or secondary cell. At Radio ResourceControl (RRC) connection establishment, re-establishment, handover,etc., a serving cell may provide NAS (non-access stratum) mobilityinformation (e.g., Tracking Area Identifier (TAI)). At RRC connectionre-establishment and/or handover, a serving cell may provide securityinput. This serving cell may be referred to as the Primary Cell (PCell).In the downlink, a carrier corresponding to the PCell may be a DLPrimary Component Carrier (PCC). In the uplink, a carrier may be an ULPCC. Secondary Cells (SCells) may be configured to form together with aPCell a set of serving cells, for example, depending on wireless devicecapabilities. In a downlink, a carrier corresponding to an SCell may bea downlink secondary component carrier (DL SCC). In an uplink, a carriermay be an uplink secondary component carrier (UL SCC). An SCell may ormay not have an uplink carrier.

A cell, comprising a downlink carrier and optionally an uplink carrier,may be assigned a physical cell ID and/or a cell index. A carrier(downlink and/or uplink) may belong to one cell. The cell ID and/or cellindex may identify the downlink carrier and/or uplink carrier of thecell (e.g., depending on the context it is used). A cell ID may beequally referred to as a carrier ID, and a cell index may be referred toas a carrier index. A physical cell ID and/or a cell index may beassigned to a cell. A cell ID may be determined using a synchronizationsignal transmitted via a downlink carrier. A cell index may bedetermined using RRC messages. A first physical cell ID for a firstdownlink carrier may indicate that the first physical cell ID is for acell comprising the first downlink carrier. The same concept may beused, for example, with carrier activation and/or deactivation (e.g.,secondary cell activation and/or deactivation). A first carrier that isactivated may indicate that a cell comprising the first carrier isactivated.

A base station may send (e.g., transmit) to a wireless device one ormore messages (e.g., RRC messages) comprising a plurality ofconfiguration parameters for one or more cells. One or more cells maycomprise at least one primary cell and at least one secondary cell. AnRRC message may be broadcasted and/or unicasted to the wireless device.Configuration parameters may comprise common parameters and dedicatedparameters.

Services and/or functions of an RRC sublayer may comprise at least oneof: broadcast of system information related to AS and/or NAS; paginginitiated by a 5GC and/or an NG-RAN; establishment, maintenance, and/orrelease of an RRC connection between a wireless device and an NG-RAN,which may comprise at least one of addition, modification, and/orrelease of carrier aggregation; and/or addition, modification, and/orrelease of dual connectivity in NR or between E-UTRA and NR. Servicesand/or functions of an RRC sublayer may comprise at least one ofsecurity functions comprising key management; establishment,configuration, maintenance, and/or release of Signaling Radio Bearers(SRBs) and/or Data Radio Bearers (DRBs); mobility functions which maycomprise at least one of a handover (e.g., intra NR mobility orinter-RAT mobility) and/or a context transfer; and/or a wireless devicecell selection and/or reselection and/or control of cell selection andreselection. Services and/or functions of an RRC sublayer may compriseat least one of QoS management functions; a wireless device measurementconfiguration/reporting; detection of and/or recovery from radio linkfailure; and/or NAS message transfer to and/or from a core networkentity (e.g., AMF, Mobility Management Entity (MME)) from and/or to thewireless device.

An RRC sublayer may support an RRC_Idle state, an RRC_Inactive state,and/or an RRC_Connected state for a wireless device. In an RRC_Idlestate, a wireless device may perform at least one of: Public Land MobileNetwork (PLMN) selection; receiving broadcasted system information; cellselection and/or re-selection; monitoring and/or receiving a paging formobile terminated data initiated by 5GC; paging for mobile terminateddata area managed by 5GC; and/or DRX for CN paging configured via NAS.In an RRC_Inactive state, a wireless device may perform at least one of:receiving broadcasted system information; cell selection and/orre-selection; monitoring and/or receiving a RAN and/or CN paginginitiated by an NG-RAN and/or a 5GC; RAN-based notification area (RNA)managed by an NG-RAN; and/or DRX for a RAN and/or CN paging configuredby NG-RAN/NAS. In an RRC_Idle state of a wireless device, a base station(e.g., NG-RAN) may keep a 5GC-NG-RAN connection (e.g., both C/U-planes)for the wireless device; and/or store a wireless device AS context forthe wireless device. In an RRC_Connected state of a wireless device, abase station (e.g., NG-RAN) may perform at least one of: establishmentof 5GC-NG-RAN connection (both C/U-planes) for the wireless device;storing a UE AS context for the wireless device; send (e.g., transmit)and/or receive of unicast data to and/or from the wireless device;and/or network-controlled mobility based on measurement results receivedfrom the wireless device. In an RRC_Connected state of a wirelessdevice, an NG-RAN may know a cell to which the wireless device belongs.

System information (SI) may be divided into minimum SI and other SI. Theminimum SI may be periodically broadcast. The minimum SI may comprisebasic information required for initial access and/or information foracquiring any other SI broadcast periodically and/or provisionedon-demand (e.g., scheduling information). The other SI may either bebroadcast, and/or be provisioned in a dedicated manner, such as eithertriggered by a network and/or upon request from a wireless device. Aminimum SI may be transmitted via two different downlink channels usingdifferent messages (e.g., MasterInformationBlock andSystemInformationBlockType1). Another SI may be transmitted viaSystemInformationBlockType2. For a wireless device in an RRC_Connectedstate, dedicated RRC signaling may be used for the request and deliveryof the other SI. For the wireless device in the RRC_Idle state and/or inthe RRC_Inactive state, the request may trigger a RA procedure.

A wireless device may report its radio access capability information,which may be static. A base station may request one or more indicationsof capabilities for a wireless device to report based on bandinformation. A temporary capability restriction request may be sent bythe wireless device (e.g., if allowed by a network) to signal thelimited availability of some capabilities (e.g., due to hardwaresharing, interference, and/or overheating) to the base station. The basestation may confirm or reject the request. The temporary capabilityrestriction may be transparent to 5GC (e.g., static capabilities may bestored in 5GC).

A wireless device may have an RRC connection with a network, forexample, if CA is configured. At RRC connection establishment,re-establishment, and/or handover procedures, a serving cell may provideNAS mobility information. At RRC connection re-establishment and/orhandover, a serving cell may provide a security input. This serving cellmay be referred to as the PCell. SCells may be configured to formtogether with the PCell a set of serving cells, for example, dependingon the capabilities of the wireless device. The configured set ofserving cells for the wireless device may comprise a PCell and one ormore SCells.

The reconfiguration, addition, and/or removal of SCells may be performedby RRC messaging. At intra-NR handover, RRC may add, remove, and/orreconfigure SCells for usage with the target PCell. Dedicated RRCsignaling may be used (e.g., if adding a new SCell) to send all requiredsystem information of the SCell (e.g., if in connected mode, wirelessdevices may not acquire broadcasted system information directly from theSCells).

The purpose of an RRC connection reconfiguration procedure may be tomodify an RRC connection, (e.g., to establish, modify, and/or releaseRBs; to perform handover; to setup, modify, and/or release measurements,for example, to add, modify, and/or release SCells and cell groups). NASdedicated information may be transferred from the network to thewireless device, for example, as part of the RRC connectionreconfiguration procedure. The RRCConnectionReconfiguration message maybe a command to modify an RRC connection. One or more RRC messages mayconvey information for measurement configuration, mobility control,and/or radio resource configuration (e.g., RBs, MAC main configuration,and/or physical channel configuration), which may comprise anyassociated dedicated NAS information and/or security configuration. Thewireless device may perform an SCell release, for example, if thereceived RRC Connection Reconfiguration message comprises thesCellToReleaseList. The wireless device may perform SCell additions ormodification, for example, if the received RRC ConnectionReconfiguration message comprises the sCellToAddModList.

An RRC connection establishment, reestablishment, and/or resumeprocedure may be to establish, reestablish, and/or resume an RRCconnection, respectively. An RRC connection establishment procedure maycomprise SRB1 establishment. The RRC connection establishment proceduremay be used to transfer the initial NAS dedicated information and/ormessage from a wireless device to an E-UTRAN. TheRRCConnectionReestablishment message may be used to re-establish SRB1.

A measurement report procedure may be used to transfer measurementresults from a wireless device to an NG-RAN. The wireless device mayinitiate a measurement report procedure, for example, after successfulsecurity activation. A measurement report message may be used to send(e.g., transmit) measurement results.

The wireless device 110 may comprise at least one communicationinterface 310 (e.g., a wireless modem, an antenna, and/or the like), atleast one processor 314, and at least one set of program codeinstructions 316 that may be stored in non-transitory memory 315 andexecutable by the at least one processor 314. The wireless device 110may further comprise at least one of at least one speaker and/ormicrophone 311, at least one keypad 312, at least one display and/ortouchpad 313, at least one power source 317, at least one globalpositioning system (GPS) chipset 318, and/or other peripherals 319.

The processor 314 of the wireless device 110, the processor 321A of thebase station 1 120A, and/or the processor 321B of the base station 2120B may comprise at least one of a general-purpose processor, a digitalsignal processor (DSP), a controller, a microcontroller, an applicationspecific integrated circuit (ASIC), a field programmable gate array(FPGA) and/or other programmable logic device, discrete gate and/ortransistor logic, discrete hardware components, and/or the like. Theprocessor 314 of the wireless device 110, the processor 321A in basestation 1 120A, and/or the processor 321B in base station 2 120B mayperform at least one of signal coding and/or processing, dataprocessing, power control, input/output processing, and/or any otherfunctionality that may enable the wireless device 110, the base station1 120A and/or the base station 2 120B to operate in a wirelessenvironment.

The processor 314 of the wireless device 110 may be connected to and/orin communication with the speaker and/or microphone 311, the keypad 312,and/or the display and/or touchpad 313. The processor 314 may receiveuser input data from and/or provide user output data to the speakerand/or microphone 311, the keypad 312, and/or the display and/ortouchpad 313. The processor 314 in the wireless device 110 may receivepower from the power source 317 and/or may be configured to distributethe power to the other components in the wireless device 110. The powersource 317 may comprise at least one of one or more dry cell batteries,solar cells, fuel cells, and/or the like. The processor 314 may beconnected to the GPS chipset 318. The GPS chipset 318 may be configuredto provide geographic location information of the wireless device 110.

The processor 314 of the wireless device 110 may further be connected toand/or in communication with other peripherals 319, which may compriseone or more software and/or hardware modules that may provide additionalfeatures and/or functionalities. For example, the peripherals 319 maycomprise at least one of an accelerometer, a satellite transceiver, adigital camera, a universal serial bus (USB) port, a hands-free headset,a frequency modulated (FM) radio unit, a media player, an Internetbrowser, and/or the like.

The communication interface 320A of the base station 1, 120A, and/or thecommunication interface 320B of the base station 2, 120B, may beconfigured to communicate with the communication interface 310 of thewireless device 110, for example, via a wireless link 330A and/or via awireless link 330B, respectively. The communication interface 320A ofthe base station 1, 120A, may communicate with the communicationinterface 320B of the base station 2 and/or other RAN and/or corenetwork nodes.

The wireless link 330A and/or the wireless link 330B may comprise atleast one of a bi-directional link and/or a directional link. Thecommunication interface 310 of the wireless device 110 may be configuredto communicate with the communication interface 320A of the base station1 120A and/or with the communication interface 320B of the base station2 120B. The base station 1 120A and the wireless device 110, and/or thebase station 2 120B and the wireless device 110, may be configured tosend and receive TBs, for example, via the wireless link 330A and/or viathe wireless link 330B, respectively. The wireless link 330A and/or thewireless link 330B may use at least one frequency carrier.Transceiver(s) may be used. A transceiver may be a device that comprisesboth a transmitter and a receiver. Transceivers may be used in devicessuch as wireless devices, base stations, relay nodes, computing devices,and/or the like. Radio technology may be implemented in thecommunication interface 310, 320A, and/or 320B, and the wireless link330A and/or 330B. The radio technology may comprise one or more elementsshown in FIG. 4A, FIG. 4B, FIG. 4C, FIG. 4D, FIG. 6, FIG. 7A, FIG. 7B,FIG. 8, and associated text, described below.

Other nodes in a wireless network (e.g., AMF, UPF, SMF, etc.) maycomprise one or more communication interfaces, one or more processors,and memory storing instructions. A node (e.g., wireless device, basestation, AMF, SMF, UPF, servers, switches, antennas, and/or the like)may comprise one or more processors, and memory storing instructionsthat when executed by the one or more processors causes the node toperform certain processes and/or functions. Single-carrier and/ormulti-carrier communication operation may be performed. A non-transitorytangible computer readable media may comprise instructions executable byone or more processors to cause operation of single-carrier and/ormulti-carrier communications. An article of manufacture may comprise anon-transitory tangible computer readable machine-accessible mediumhaving instructions encoded thereon for enabling programmable hardwareto cause a node to enable operation of single-carrier and/ormulti-carrier communications. The node may comprise processors, memory,interfaces, and/or the like.

An interface may comprise at least one of a hardware interface, afirmware interface, a software interface, and/or a combination thereof.The hardware interface may comprise connectors, wires, and/or electronicdevices such as drivers, amplifiers, and/or the like. The softwareinterface may comprise code stored in a memory device to implementprotocol(s), protocol layers, communication drivers, device drivers,combinations thereof, and/or the like. The firmware interface maycomprise a combination of embedded hardware and/or code stored in(and/or in communication with) a memory device to implement connections,electronic device operations, protocol(s), protocol layers,communication drivers, device drivers, hardware operations, combinationsthereof, and/or the like.

A communication network may comprise the wireless device 110, the basestation 1, 120A, the base station 2, 120B, and/or any other device. Thecommunication network may comprise any number and/or type of devices,such as, for example, computing devices, wireless devices, mobiledevices, handsets, tablets, laptops, internet of things (IoT) devices,hotspots, cellular repeaters, computing devices, and/or, more generally,user equipment (e.g., UE). Although one or more of the above types ofdevices may be referenced herein (e.g., UE, wireless device, computingdevice, etc.), it should be understood that any device herein maycomprise any one or more of the above types of devices or similardevices. The communication network, and any other network referencedherein, may comprise an LTE network, a 5G network, or any other networkfor wireless communications. Apparatuses, systems, and/or methodsdescribed herein may generally be described as implemented on one ormore devices (e.g., wireless device, base station, eNB, gNB, computingdevice, etc.), in one or more networks, but it will be understood thatone or more features and steps may be implemented on any device and/orin any network. As used throughout, the term “base station” may compriseone or more of: a base station, a node, a Node B, a gNB, an eNB, anng-eNB, a relay node (e.g., an integrated access and backhaul (IAB)node), a donor node (e.g., a donor eNB, a donor gNB, etc.), an accesspoint (e.g., a WiFi access point), a computing device, a device capableof wirelessly communicating, or any other device capable of sendingand/or receiving signals. As used throughout, the term “wireless device”may comprise one or more of: a UE, a handset, a mobile device, acomputing device, a node, a device capable of wirelessly communicating,or any other device capable of sending and/or receiving signals. Anyreference to one or more of these terms/devices also considers use ofany other term/device mentioned above.

FIG. 4A, FIG. 4B, FIG. 4C and FIG. 4D show examples of uplink anddownlink signal transmission. FIG. 4A shows an example uplinktransmitter for at least one physical channel A baseband signalrepresenting a physical uplink shared channel may perform one or morefunctions. The one or more functions may comprise at least one of:scrambling (e.g., by Scrambling); modulation of scrambled bits togenerate complex-valued symbols (e.g., by a Modulation mapper); mappingof the complex-valued modulation symbols onto one or severaltransmission layers (e.g., by a Layer mapper); transform precoding togenerate complex-valued symbols (e.g., by a Transform precoder);precoding of the complex-valued symbols (e.g., by a Precoder); mappingof precoded complex-valued symbols to resource elements (e.g., by aResource element mapper); generation of complex-valued time-domainSingle Carrier-Frequency Division Multiple Access (SC-FDMA) or CP-OFDMsignal for an antenna port (e.g., by a signal gen.); and/or the like. ASC-FDMA signal for uplink transmission may be generated, for example, iftransform precoding is enabled. A CP-OFDM signal for uplink transmissionmay be generated by FIG. 4A, for example, if transform precoding is notenabled. These functions are shown as examples and other mechanisms maybe implemented.

FIG. 4B shows an example of modulation and up-conversion to the carrierfrequency of a complex-valued SC-FDMA or CP-OFDM baseband signal for anantenna port and/or for the complex-valued Physical Random AccessCHannel (PRACH) baseband signal. Filtering may be performed prior totransmission.

FIG. 4C shows an example of downlink transmissions. The baseband signalrepresenting a downlink physical channel may perform one or morefunctions. The one or more functions may comprise: scrambling of codedbits in a codeword to be transmitted on a physical channel (e.g., byScrambling); modulation of scrambled bits to generate complex-valuedmodulation symbols (e.g., by a Modulation mapper); mapping of thecomplex-valued modulation symbols onto one or several transmissionlayers (e.g., by a Layer mapper); precoding of the complex-valuedmodulation symbols on a layer for transmission on the antenna ports(e.g., by Precoding); mapping of complex-valued modulation symbols foran antenna port to resource elements (e.g., by a Resource elementmapper); generation of complex-valued time-domain OFDM signal for anantenna port (e.g., by an OFDM signal gen.); and/or the like. Thesefunctions are shown as examples and other mechanisms may be implemented.

A base station may send (e.g., transmit) a first symbol and a secondsymbol on an antenna port, to a wireless device. The wireless device mayinfer the channel (e.g., fading gain, multipath delay, etc.) forconveying the second symbol on the antenna port, from the channel forconveying the first symbol on the antenna port. A first antenna port anda second antenna port may be quasi co-located, for example, if one ormore large-scale properties of the channel over which a first symbol onthe first antenna port is conveyed may be inferred from the channel overwhich a second symbol on a second antenna port is conveyed. The one ormore large-scale properties may comprise at least one of: delay spread;Doppler spread; Doppler shift; average gain; average delay; and/orspatial receiving (Rx) parameters.

FIG. 4D shows an example modulation and up-conversion to the carrierfrequency of the complex-valued OFDM baseband signal for an antennaport. Filtering may be performed prior to transmission.

FIG. 5A shows example uplink channel mapping and example uplink physicalsignals. A physical layer may provide one or more information transferservices to a MAC and/or one or more higher layers. The physical layermay provide the one or more information transfer services to the MAC viaone or more transport channels. An information transfer service mayindicate how and/or with what characteristics data is transferred overthe radio interface.

Uplink transport channels may comprise an Uplink-Shared CHannel (UL-SCH)501 and/or a Random Access CHannel (RACH) 502. A wireless device maysend (e.g., transmit) one or more uplink DM-RSs 506 to a base stationfor channel estimation, for example, for coherent demodulation of one ormore uplink physical channels (e.g., PUSCH 503 and/or PUCCH 504). Thewireless device may send (e.g., transmit) to a base station at least oneuplink DM-RS 506 with PUSCH 503 and/or PUCCH 504, wherein the at leastone uplink DM-RS 506 may be spanning a same frequency range as acorresponding physical channel. The base station may configure thewireless device with one or more uplink DM-RS configurations. At leastone DM-RS configuration may support a front-loaded DM-RS pattern. Afront-loaded DM-RS may be mapped over one or more OFDM symbols (e.g., 1or 2 adjacent OFDM symbols). One or more additional uplink DM-RS may beconfigured to send (e.g., transmit) at one or more symbols of a PUSCHand/or PUCCH. The base station may semi-statically configure thewireless device with a maximum number of front-loaded DM-RS symbols forPUSCH and/or PUCCH. The wireless device may schedule a single-symbolDM-RS and/or double symbol DM-RS based on a maximum number offront-loaded DM-RS symbols, wherein the base station may configure thewireless device with one or more additional uplink DM-RS for PUSCHand/or PUCCH. A new radio network may support, for example, at least forCP-OFDM, a common DM-RS structure for DL and UL, wherein a DM-RSlocation, DM-RS pattern, and/or scrambling sequence may be same ordifferent.

Whether or not an uplink PT-RS 507 is present may depend on an RRCconfiguration. A presence of the uplink PT-RS may be wirelessdevice-specifically configured. A presence and/or a pattern of theuplink PT-RS 507 in a scheduled resource may be wirelessdevice-specifically configured by a combination of RRC signaling and/orassociation with one or more parameters used for other purposes (e.g.,Modulation and Coding Scheme (MCS)) which may be indicated by DCI. Ifconfigured, a dynamic presence of uplink PT-RS 507 may be associatedwith one or more DCI parameters comprising at least a MCS. A radionetwork may support a plurality of uplink PT-RS densities defined intime/frequency domain. If present, a frequency domain density may beassociated with at least one configuration of a scheduled bandwidth. Awireless device may assume a same precoding for a DMRS port and a PT-RSport. A number of PT-RS ports may be less than a number of DM-RS portsin a scheduled resource. The uplink PT-RS 507 may be confined in thescheduled time/frequency duration for a wireless device.

A wireless device may send (e.g., transmit) an SRS 508 to a base stationfor channel state estimation, for example, to support uplink channeldependent scheduling and/or link adaptation. The SRS 508 sent (e.g.,transmitted) by the wireless device may allow for the base station toestimate an uplink channel state at one or more different frequencies. Abase station scheduler may use an uplink channel state to assign one ormore resource blocks of a certain quality (e.g., above a qualitythreshold) for an uplink PUSCH transmission from the wireless device.The base station may semi-statically configure the wireless device withone or more SRS resource sets. For an SRS resource set, the base stationmay configure the wireless device with one or more SRS resources. An SRSresource set applicability may be configured by a higher layer (e.g.,RRC) parameter. An SRS resource in each of one or more SRS resource setsmay be sent (e.g., transmitted) at a time instant, for example, if ahigher layer parameter indicates beam management. The wireless devicemay send (e.g., transmit) one or more SRS resources in different SRSresource sets simultaneously. A new radio network may support aperiodic,periodic, and/or semi-persistent SRS transmissions. The wireless devicemay send (e.g., transmit) SRS resources, for example, based on one ormore trigger types. The one or more trigger types may comprise higherlayer signaling (e.g., RRC) and/or one or more DCI formats (e.g., atleast one DCI format may be used for a wireless device to select atleast one of one or more configured SRS resource sets). An SRS triggertype 0 may refer to an SRS triggered based on a higher layer signaling.An SRS trigger type 1 may refer to an SRS triggered based on one or moreDCI formats. The wireless device may be configured to send (e.g.,transmit) the SRS 508 after a transmission of PUSCH 503 andcorresponding uplink DM-RS 506, for example, if PUSCH 503 and the SRS508 are transmitted in a same slot.

A base station may semi-statically configure a wireless device with oneor more SRS configuration parameters indicating at least one offollowing: an SRS resource configuration identifier, a number of SRSports, time domain behavior of SRS resource configuration (e.g., anindication of periodic, semi-persistent, or aperiodic SRS), slot(mini-slot, and/or subframe) level periodicity and/or offset for aperiodic and/or aperiodic SRS resource, a number of OFDM symbols in aSRS resource, starting OFDM symbol of a SRS resource, an SRS bandwidth,a frequency hopping bandwidth, a cyclic shift, and/or an SRS sequenceID.

FIG. 5B shows an example downlink channel mapping and downlink physicalsignals. Downlink transport channels may comprise a Downlink-SharedCHannel (DL-SCH) 511, a Paging CHannel (PCH) 512, and/or a BroadcastCHannel (BCH) 513. A transport channel may be mapped to one or morecorresponding physical channels. A UL-SCH 501 may be mapped to aPhysical Uplink Shared CHannel (PUSCH) 503. A RACH 502 may be mapped toa PRACH 505. A DL-SCH 511 and a PCH 512 may be mapped to a PhysicalDownlink Shared CHannel (PDSCH) 514. A BCH 513 may be mapped to aPhysical Broadcast CHannel (PBCH) 516.

A radio network may comprise one or more downlink and/or uplinktransport channels. The radio network may comprise one or more physicalchannels without a corresponding transport channel. The one or morephysical channels may be used for an Uplink Control Information (UCI)509 and/or a Downlink Control Information (DCI) 517. A Physical UplinkControl CHannel (PUCCH) 504 may carry UCI 509 from a wireless device toa base station. A Physical Downlink Control CHannel (PDCCH) 515 maycarry the DCI 517 from a base station to a wireless device. The radionetwork (e.g., NR) may support the UCI 509 multiplexing in the PUSCH503, for example, if the UCI 509 and the PUSCH 503 transmissions maycoincide in a slot (e.g., at least in part). The UCI 509 may comprise atleast one of a CSI, an Acknowledgement (ACK)/Negative Acknowledgement(NACK), and/or a scheduling request. The DCI 517 via the PDCCH 515 mayindicate at least one of following: one or more downlink assignmentsand/or one or more uplink scheduling grants.

In uplink, a wireless device may send (e.g., transmit) one or moreReference Signals (RSs) to a base station. The one or more RSs maycomprise at least one of a Demodulation-RS (DM-RS) 506, a PhaseTracking-RS (PT-RS) 507, and/or a Sounding RS (SRS) 508. In downlink, abase station may send (e.g., transmit, unicast, multicast, and/orbroadcast) one or more RSs to a wireless device. The one or more RSs maycomprise at least one of a Primary Synchronization Signal(PSS)/Secondary Synchronization Signal (SSS) 521, a CSI-RS 522, a DM-RS523, and/or a PT-RS 524.

In a time domain, an SS/PBCH block (SSB) may comprise one or more OFDMsymbols (e.g., 4 OFDM symbols numbered in increasing order from 0 to 3)within the SS/PBCH block. An SS/PBCH block may comprise the PSS/SSS 521and/or the PBCH 516. In the frequency domain, an SS/PBCH block maycomprise one or more contiguous subcarriers (e.g., 240 contiguoussubcarriers with the subcarriers numbered in increasing order from 0 to239) within the SS/PBCH block. The PSS/SSS 521 may occupy, for example,1 OFDM symbol and 127 subcarriers. The PBCH 516 may span across, forexample, 3 OFDM symbols and 240 subcarriers. A wireless device mayassume that one or more SS/PBCH blocks transmitted with a same blockindex may be quasi co-located, for example, with respect to Dopplerspread, Doppler shift, average gain, average delay, and/or spatial Rxparameters. A wireless device may not assume quasi co-location for otherSS/PBCH block transmissions. A periodicity of an SS/PBCH block may beconfigured by a radio network (e.g., by an RRC signaling). One or moretime locations in which the SS/PBCH block may be sent may be determinedby sub-carrier spacing. A wireless device may assume a band-specificsub-carrier spacing for an SS/PBCH block, for example, unless a radionetwork has configured the wireless device to assume a differentsub-carrier spacing.

The downlink CSI-RS 522 may be used for a wireless device to acquirechannel state information. A radio network may support periodic,aperiodic, and/or semi-persistent transmission of the downlink CSI-RS522. A base station may semi-statically configure and/or reconfigure awireless device with periodic transmission of the downlink CSI-RS 522. Aconfigured CSI-RS resources may be activated and/or deactivated. Forsemi-persistent transmission, an activation and/or deactivation of aCSI-RS resource may be triggered dynamically. A CSI-RS configuration maycomprise one or more parameters indicating at least a number of antennaports. A base station may configure a wireless device with 32 ports, orany other number of ports. A base station may semi-statically configurea wireless device with one or more CSI-RS resource sets. One or moreCSI-RS resources may be allocated from one or more CSI-RS resource setsto one or more wireless devices. A base station may semi-staticallyconfigure one or more parameters indicating CSI RS resource mapping, forexample, time-domain location of one or more CSI-RS resources, abandwidth of a CSI-RS resource, and/or a periodicity. A wireless devicemay be configured to use the same OFDM symbols for the downlink CSI-RS522 and the Control Resource Set (CORESET), for example, if the downlinkCSI-RS 522 and the CORESET are spatially quasi co-located and resourceelements associated with the downlink CSI-RS 522 are the outside of PRBsconfigured for the CORESET. A wireless device may be configured to usethe same OFDM symbols for downlink CSI-RS 522 and SSB/PBCH, for example,if the downlink CSI-RS 522 and SSB/PBCH are spatially quasi co-locatedand resource elements associated with the downlink CSI-RS 522 areoutside of the PRBs configured for the SSB/PBCH.

A wireless device may send (e.g., transmit) one or more downlink DM-RSs523 to a base station for channel estimation, for example, for coherentdemodulation of one or more downlink physical channels (e.g., PDSCH514). A radio network may support one or more variable and/orconfigurable DM-RS patterns for data demodulation. At least one downlinkDM-RS configuration may support a front-loaded DM-RS pattern. Afront-loaded DM-RS may be mapped over one or more OFDM symbols (e.g., 1or 2 adjacent OFDM symbols). A base station may semi-staticallyconfigure a wireless device with a maximum number of front-loaded DM-RSsymbols for PDSCH 514. A DM-RS configuration may support one or moreDM-RS ports. A DM-RS configuration may support at least 8 orthogonaldownlink DM-RS ports, for example, for single user-MIMO. ADM-RSconfiguration may support 12 orthogonal downlink DM-RS ports, forexample, for multiuser-MIMO. A radio network may support, for example,at least for CP-OFDM, a common DM-RS structure for DL and UL, wherein aDM-RS location, DM-RS pattern, and/or scrambling sequence may be thesame or different.

Whether or not the downlink PT-RS 524 is present may depend on an RRCconfiguration. A presence of the downlink PT-RS 524 may be wirelessdevice-specifically configured. A presence and/or a pattern of thedownlink PT-RS 524 in a scheduled resource may be wirelessdevice-specifically configured, for example, by a combination of RRCsignaling and/or an association with one or more parameters used forother purposes (e.g., MCS) which may be indicated by the DCI. Ifconfigured, a dynamic presence of the downlink PT-RS 524 may beassociated with one or more DCI parameters comprising at least MCS. Aradio network may support a plurality of PT-RS densities in atime/frequency domain. If present, a frequency domain density may beassociated with at least one configuration of a scheduled bandwidth. Awireless device may assume the same precoding for a DMRS port and aPT-RS port. A number of PT-RS ports may be less than a number of DM-RSports in a scheduled resource. The downlink PT-RS 524 may be confined inthe scheduled time/frequency duration for a wireless device.

FIG. 6 shows an example transmission and/or reception time of a carrier,as well as an example frame structure, for a carrier. A multicarrierOFDM communication system may comprise one or more carriers, forexample, ranging from 1 to 32 carriers (such as for carrier aggregation)or ranging from 1 to 64 carriers (such as for dual connectivity).Different radio frame structures may be supported (e.g., for FDD and/orfor TDD duplex mechanisms). FIG. 6 shows an example frame structure.Downlink and uplink transmissions may be organized into radio frames601. Radio frame duration may be 10 milliseconds (ms). A 10 ms radioframe 601 may be divided into ten equally sized subframes 602, each witha 1 ms duration. Subframe(s) may comprise one or more slots (e.g., slots603 and 605) depending on subcarrier spacing and/or CP length. Forexample, a subframe with 15 kHz, 30 kHz, 60 kHz, 120 kHz, 240 kHz and480 kHz subcarrier spacing may comprise one, two, four, eight, sixteenand thirty-two slots, respectively. In FIG. 6, a subframe may be dividedinto two equally sized slots 603 with 0.5 ms duration. For example, 10subframes may be available for downlink transmission and 10 subframesmay be available for uplink transmissions in a 10 ms interval. Othersubframe durations such as, for example, 0.5 ms, 1 ms, 2 ms, and 5 msmay be supported. Uplink and downlink transmissions may be separated inthe frequency domain. Slot(s) may comprise a plurality of OFDM symbols604. The number of OFDM symbols 604 in a slot 605 may depend on thecyclic prefix length. A slot may be 14 OFDM symbols for the samesubcarrier spacing of up to 480 kHz with normal CP. A slot may be 12OFDM symbols for the same subcarrier spacing of 60 kHz with extended CP.A slot may comprise downlink, uplink, and/or a downlink part and anuplink part, and/or alike.

FIG. 7A shows example sets of OFDM subcarriers. A base station maycommunicate with a wireless device using a carrier having an examplechannel bandwidth 700. Arrow(s) may depict a subcarrier in amulticarrier OFDM system. The OFDM system may use technology such asOFDM technology, SC-FDMA technology, and/or the like. An arrow 701 showsa subcarrier transmitting information symbols. A subcarrier spacing 702,between two contiguous subcarriers in a carrier, may be any one of 15kHz, 30 kHz, 60 kHz, 120 kHz, 240 kHz, or any other frequency. Differentsubcarrier spacing may correspond to different transmissionnumerologies. A transmission numerology may comprise at least: anumerology index; a value of subcarrier spacing; and/or a type of cyclicprefix (CP). A base station may send (e.g., transmit) to and/or receivefrom a wireless device via a number of subcarriers 703 in a carrier. Abandwidth occupied by a number of subcarriers 703 (e.g., transmissionbandwidth) may be smaller than the channel bandwidth 700 of a carrier,for example, due to guard bands 704 and 705. Guard bands 704 and 705 maybe used to reduce interference to and from one or more neighborcarriers. A number of subcarriers (e.g., transmission bandwidth) in acarrier may depend on the channel bandwidth of the carrier and/or thesubcarrier spacing. A transmission bandwidth, for a carrier with a 20MHz channel bandwidth and a 15 kHz subcarrier spacing, may be in numberof 1024 subcarriers.

A base station and a wireless device may communicate with multiplecomponent carriers (CCs), for example, if configured with CA. Differentcomponent carriers may have different bandwidth and/or differentsubcarrier spacing, for example, if CA is supported. A base station maysend (e.g., transmit) a first type of service to a wireless device via afirst component carrier. The base station may send (e.g., transmit) asecond type of service to the wireless device via a second componentcarrier. Different types of services may have different servicerequirements (e.g., data rate, latency, reliability), which may besuitable for transmission via different component carriers havingdifferent subcarrier spacing and/or different bandwidth.

FIG. 7B shows examples of component carriers. A first component carriermay comprise a first number of subcarriers 706 having a first subcarrierspacing 709. A second component carrier may comprise a second number ofsubcarriers 707 having a second subcarrier spacing 710. A thirdcomponent carrier may comprise a third number of subcarriers 708 havinga third subcarrier spacing 711. Carriers in a multicarrier OFDMcommunication system may be contiguous carriers, non-contiguouscarriers, or a combination of both contiguous and non-contiguouscarriers.

FIG. 8 shows an example of OFDM radio resources. A carrier may have atransmission bandwidth 801. A resource grid may be in a structure offrequency domain 802 and time domain 803. A resource grid may comprise afirst number of OFDM symbols in a subframe and a second number ofresource blocks, starting from a common resource block indicated byhigher-layer signaling (e.g., RRC signaling), for a transmissionnumerology and a carrier. In a resource grid, a resource element 805 maycomprise a resource unit that may be identified by a subcarrier indexand a symbol index. A subframe may comprise a first number of OFDMsymbols 807 that may depend on a numerology associated with a carrier. Asubframe may have 14 OFDM symbols for a carrier, for example, if asubcarrier spacing of a numerology of a carrier is 15 kHz. A subframemay have 28 OFDM symbols, for example, if a subcarrier spacing of anumerology is 30 kHz. A subframe may have 56 OFDM symbols, for example,if a subcarrier spacing of a numerology is 60 kHz. A subcarrier spacingof a numerology may comprise any other frequency. A second number ofresource blocks comprised in a resource grid of a carrier may depend ona bandwidth and a numerology of the carrier.

A resource block 806 may comprise 12 subcarriers. Multiple resourceblocks may be grouped into a Resource Block Group (RBG) 804. A size of aRBG may depend on at least one of: a RRC message indicating a RBG sizeconfiguration; a size of a carrier bandwidth; and/or a size of a BWP ofa carrier. A carrier may comprise multiple BWPs. A first BWP of acarrier may have a different frequency location and/or a differentbandwidth from a second BWP of the carrier.

A base station may send (e.g., transmit), to a wireless device, adownlink control information comprising a downlink or uplink resourceblock assignment. A base station may send (e.g., transmit) to and/orreceive from, a wireless device, data packets (e.g., TBs). The datapackets may be scheduled on and transmitted via one or more resourceblocks and one or more slots indicated by parameters in downlink controlinformation and/or RRC message(s). A starting symbol relative to a firstslot of the one or more slots may be indicated to the wireless device. Abase station may send (e.g., transmit) to and/or receive from, awireless device, data packets. The data packets may be scheduled fortransmission on one or more RBGs and in one or more slots.

A base station may send (e.g., transmit), to a wireless device, downlinkcontrol information comprising a downlink assignment. The base stationmay send (e.g., transmit) the DCI via one or more PDCCHs. The downlinkassignment may comprise parameters indicating at least one of amodulation and coding format; resource allocation; and/or HARQinformation related to the DL-SCH. The resource allocation may compriseparameters of resource block allocation; and/or slot allocation. A basestation may allocate (e.g., dynamically) resources to a wireless device,for example, via a Cell-Radio Network Temporary Identifier (C-RNTI) onone or more PDCCHs. The wireless device may monitor the one or morePDCCHs, for example, in order to find possible allocation if itsdownlink reception is enabled. The wireless device may receive one ormore downlink data packets on one or more PDSCH scheduled by the one ormore PDCCHs, for example, if the wireless device successfully detectsthe one or more PDCCHs.

A base station may allocate Configured Scheduling (CS) resources fordown link transmission to a wireless device. The base station may send(e.g., transmit) one or more RRC messages indicating a periodicity ofthe CS grant. The base station may send (e.g., transmit) DCI via a PDCCHaddressed to a Configured Scheduling-RNTI (CS-RNTI) activating the CSresources. The DCI may comprise parameters indicating that the downlinkgrant is a CS grant. The CS grant may be implicitly reused according tothe periodicity defined by the one or more RRC messages. The CS grantmay be implicitly reused, for example, until deactivated.

A base station may send (e.g., transmit), to a wireless device via oneor more PDCCHs, downlink control information comprising an uplink grant.The uplink grant may comprise parameters indicating at least one of amodulation and coding format; a resource allocation; and/or HARQinformation related to the UL-SCH. The resource allocation may compriseparameters of resource block allocation; and/or slot allocation. Thebase station may dynamically allocate resources to the wireless devicevia a C-RNTI on one or more PDCCHs. The wireless device may monitor theone or more PDCCHs, for example, in order to find possible resourceallocation. The wireless device may send (e.g., transmit) one or moreuplink data packets via one or more PUSCH scheduled by the one or morePDCCHs, for example, if the wireless device successfully detects the oneor more PDCCHs.

The base station may allocate CS resources for uplink data transmissionto a wireless device. The base station may transmit one or more RRCmessages indicating a periodicity of the CS grant. The base station maysend (e.g., transmit) DCI via a PDCCH addressed to a CS-RNTI to activatethe CS resources. The DCI may comprise parameters indicating that theuplink grant is a CS grant. The CS grant may be implicitly reusedaccording to the periodicity defined by the one or more RRC message, TheCS grant may be implicitly reused, for example, until deactivated.

A base station may send (e.g., transmit) DCI and/or control signalingvia a PDCCH. The DCI may comprise a format of a plurality of formats.The DCI may comprise downlink and/or uplink scheduling information(e.g., resource allocation information, HARQ related parameters, MCS),request(s) for CSI (e.g., aperiodic CQI reports), request(s) for an SRS,uplink power control commands for one or more cells, one or more timinginformation (e.g., TB transmission/reception timing, HARQ feedbacktiming, etc.), and/or the like. The DCI may indicate an uplink grantcomprising transmission parameters for one or more TBs. The DCI mayindicate a downlink assignment indicating parameters for receiving oneor more TBs. The DCI may be used by the base station to initiate acontention-free RA at the wireless device. The base station may send(e.g., transmit) DCI comprising a slot format indicator (SFI) indicatinga slot format. The base station may send (e.g., transmit) DCI comprisinga preemption indication indicating the PRB(s) and/or OFDM symbol(s) inwhich a wireless device may assume no transmission is intended for thewireless device. The base station may send (e.g., transmit) DCI forgroup power control of the PUCCH, the PUSCH, and/or an SRS. DCI maycorrespond to an RNTI. The wireless device may obtain an RNTI after orin response to completing the initial access (e.g., C-RNTI). The basestation may configure an RNTI for the wireless (e.g., CS-RNTI,TPC-CS-RNTI, TPC-PUCCH-RNTI, TPC-PUSCH-RNTI, TPC-SRS-RNTI, etc.). Thewireless device may determine (e.g., compute) an RNTI (e.g., thewireless device may determine the RA-RNTI based on resources used fortransmission of a preamble). An RNTI may have a pre-configured value(e.g., P-RNTI or SI-RNTI). The wireless device may monitor a groupcommon search space which may be used by the base station for sending(e.g., transmitting) DCIs that are intended for a group of wirelessdevices. A group common DCI may correspond to an RNTI which is commonlyconfigured for a group of wireless devices. The wireless device maymonitor a wireless device-specific search space. A wireless devicespecific DCI may correspond to an RNTI configured for the wirelessdevice.

A communications system (e.g., an NR system) may support a single beamoperation and/or a multi-beam operation. In a multi-beam operation, abase station may perform a downlink beam sweeping to provide coveragefor common control channels and/or downlink SS blocks, which maycomprise at least a PSS, a SSS, and/or PBCH. A wireless device maymeasure quality of a beam pair link using one or more RSs. One or moreSS blocks, or one or more CSI-RS resources (e.g., which may beassociated with a CSI-RS resource index (CRI)), and/or one or moreDM-RSs of a PBCH, may be used as an RS for measuring a quality of a beampair link. The quality of a beam pair link may be based on a referencesignal received power (RSRP) value, a reference signal received quality(RSRQ) value, and/or a CSI value measured on RS resources. The basestation may indicate whether an RS resource, used for measuring a beampair link quality, is quasi-co-located (QCLed) with DM-RSs of a controlchannel. An RS resource and DM-RSs of a control channel may be calledQCLed, for example, if channel characteristics from a transmission on anRS to a wireless device, and that from a transmission on a controlchannel to a wireless device, are similar or the same under a configuredcriterion. In a multi-beam operation, a wireless device may perform anuplink beam sweeping to access a cell.

A wireless device may be configured to monitor a PDCCH on one or morebeam pair links simultaneously, for example, depending on a capabilityof the wireless device. This monitoring may increase robustness againstbeam pair link blocking. A base station may send (e.g., transmit) one ormore messages to configure the wireless device to monitor the PDCCH onone or more beam pair links in different PDCCH OFDM symbols. A basestation may send (e.g., transmit) higher layer signaling (e.g., RRCsignaling) and/or a MAC CE comprising parameters related to the Rx beamsetting of the wireless device for monitoring the PDCCH on one or morebeam pair links. The base station may send (e.g., transmit) anindication of a spatial QCL assumption between an DL RS antenna port(s)(e.g., a cell-specific CSI-RS, a wireless device-specific CSI-RS, an SSblock, and/or a PBCH with or without DM-RSs of the PBCH) and/or DL RSantenna port(s) for demodulation of a DL control channel. Signaling forbeam indication for a PDCCH may comprise MAC CE signaling, RRCsignaling, DCI signaling, and/or specification-transparent and/orimplicit method, and/or any combination of signaling methods.

A base station may indicate spatial QCL parameters between DL RS antennaport(s) and DM-RS antenna port(s) of a DL data channel, for example, forreception of a unicast DL data channel. The base station may send (e.g.,transmit) DCI (e.g., downlink grants) comprising information indicatingthe RS antenna port(s). The information may indicate RS antenna port(s)that may be QCL-ed with the DM-RS antenna port(s). A different set ofDM-RS antenna port(s) for a DL data channel may be indicated as QCL witha different set of the RS antenna port(s).

FIG. 9A shows an example of beam sweeping in a DL channel. In anRRC_INACTIVE state or RRC_IDLE state, a wireless device may assume thatSS blocks form an SS burst 940, and an SS burst set 950. The SS burstset 950 may have a given periodicity. A base station 120 may send (e.g.,transmit) SS blocks in multiple beams, together forming a SS burst 940,for example, in a multi-beam operation. One or more SS blocks may besent (e.g., transmitted) on one beam. If multiple SS bursts 940 aretransmitted with multiple beams, SS bursts together may form SS burstset 950.

A wireless device may use CSI-RS for estimating a beam quality of a linkbetween a wireless device and a base station, for example, in the multibeam operation. A beam may be associated with a CSI-RS. A wirelessdevice may (e.g., based on a RSRP measurement on CSI-RS) report a beamindex, which may be indicated in a CRI for downlink beam selectionand/or associated with an RSRP value of a beam. A CSI-RS may be sent(e.g., transmitted) on a CSI-RS resource, which may comprise at leastone of: one or more antenna ports and/or one or more time and/orfrequency radio resources. A CSI-RS resource may be configured in acell-specific way such as by common RRC signaling, or in a wirelessdevice-specific way such as by dedicated RRC signaling and/or L1/L2signaling. Multiple wireless devices covered by a cell may measure acell-specific CSI-RS resource. A dedicated subset of wireless devicescovered by a cell may measure a wireless device-specific CSI-RSresource.

A CSI-RS resource may be sent (e.g., transmitted) periodically, usingaperiodic transmission, or using a multi-shot or semi-persistenttransmission. In a periodic transmission in FIG. 9A, a base station 120may send (e.g., transmit) configured CSI-RS resources 940 periodicallyusing a configured periodicity in a time domain. In an aperiodictransmission, a configured CSI-RS resource may be sent (e.g.,transmitted) in a dedicated time slot. In a multi-shot and/orsemi-persistent transmission, a configured CSI-RS resource may be sent(e.g., transmitted) within a configured period. Beams used for CSI-RStransmission may have a different beam width than beams used forSS-blocks transmission.

FIG. 9B shows an example of a beam management procedure, such as a newradio network. The base station 120 and/or the wireless device 110 mayperform a downlink L1/L2 beam management procedure. One or more of thefollowing downlink L1/L2 beam management procedures may be performedwithin one or more wireless devices 110 and one or more base stations120. A P1 procedure 910 may be used to enable the wireless device 110 tomeasure one or more Transmission (Tx) beams associated with the basestation 120, for example, to support a selection of a first set of Txbeams associated with the base station 120 and a first set of Rx beam(s)associated with the wireless device 110. A base station 120 may sweep aset of different Tx beams, for example, for beamforming at a basestation 120 (such as shown in the top row, in a counter-clockwisedirection). A wireless device 110 may sweep a set of different Rx beams,for example, for beamforming at a wireless device 110 (such as shown inthe bottom row, in a clockwise direction). A P2 procedure 920 may beused to enable a wireless device 110 to measure one or more Tx beamsassociated with a base station 120, for example, to possibly change afirst set of Tx beams associated with a base station 120. A P2 procedure920 may be performed on a possibly smaller set of beams (e.g., for beamrefinement) than in the P1 procedure 910. A P2 procedure 920 may be aspecial example of a P1 procedure 910. A P3 procedure 930 may be used toenable a wireless device 110 to measure at least one Tx beam associatedwith a base station 120, for example, to change a first set of Rx beamsassociated with a wireless device 110.

A wireless device 110 may send (e.g., transmit) one or more beammanagement reports to a base station 120. In one or more beam managementreports, a wireless device 110 may indicate one or more beam pairquality parameters comprising one or more of: a beam identification; anRSRP; a Precoding Matrix Indicator (PMI), Channel Quality Indicator(CQI), and/or Rank Indicator (RI) of a subset of configured beams. Basedon one or more beam management reports, the base station 120 may send(e.g., transmit) to a wireless device 110 a signal indicating that oneor more beam pair links are one or more serving beams. The base station120 may send (e.g., transmit) the PDCCH and the PDSCH for a wirelessdevice 110 using one or more serving beams.

A communications network (e.g., a new radio network) may support aBandwidth Adaptation (BA). Receive and/or transmit bandwidths that maybe configured for a wireless device using a BA may not be large. Receiveand/or transmit bandwidth may not be as large as a bandwidth of a cell.Receive and/or transmit bandwidths may be adjustable. A wireless devicemay change receive and/or transmit bandwidths, for example, to reduce(e.g., shrink) the bandwidth(s) at (e.g., during) a period of lowactivity such as to save power. A wireless device may change a locationof receive and/or transmit bandwidths in a frequency domain, forexample, to increase scheduling flexibility. A wireless device maychange a subcarrier spacing, for example, to allow different services.

A Bandwidth Part (BWP) may comprise a subset of a total cell bandwidthof a cell. A base station may configure a wireless device with one ormore BWPs, for example, to achieve a BA. A base station may indicate, toa wireless device, which of the one or more (configured) BWPs is anactive BWP.

FIG. 10 shows an example of BWP configurations. BWPs may be configuredas follows: BWP1 (1010 and 1050) with a width of 40 MHz and subcarrierspacing of 15 kHz; BWP2 (1020 and 1040) with a width of 10 MHz andsubcarrier spacing of 15 kHz; BWP3 1030 with a width of 20 MHz andsubcarrier spacing of 60 kHz. Any number of BWP configurations maycomprise any other width and subcarrier spacing combination.

A wireless device, configured for operation in one or more BWPs of acell, may be configured by one or more higher layers (e.g., RRC layer).The wireless device may be configured for a cell with: a set of one ormore BWPs (e.g., at most four BWPs) for reception (e.g., a DL BWP set)in a DL bandwidth by at least one parameter DL-BWP; and a set of one ormore BWPs (e.g., at most four BWPs) for transmissions (e.g., UL BWP set)in an UL bandwidth by at least one parameter UL-BWP.

A base station may configure a wireless device with one or more UL andDL BWP pairs, for example, to enable BA on the PCell. To enable BA onSCells (e.g., for CA), a base station may configure a wireless device atleast with one or more DL BWPs (e.g., there may be none in an UL).

An initial active DL BWP may comprise at least one of a location andnumber of contiguous PRBs, a subcarrier spacing, or a cyclic prefix, forexample, for a CORESETs for at least one common search space. Foroperation on the PCell, one or more higher layer parameters may indicateat least one initial UL BWP for a RA procedure. If a wireless device isconfigured with a secondary carrier on a primary cell, the wirelessdevice may be configured with an initial BWP for RA procedure on asecondary carrier.

A wireless device may expect that a center frequency for a DL BWP may besame as a center frequency for a UL BWP, for example, for unpairedspectrum operation. A base station may semi-statically configure awireless device for a cell with one or more parameters, for example, fora DL BWP or an UL BWP in a set of one or more DL BWPs or one or more ULBWPs, respectively. The one or more parameters may indicate one or moreof following: a subcarrier spacing; a cyclic prefix; a number ofcontiguous PRBs; an index in the set of one or more DL BWPs and/or oneor more UL BWPs; a link between a DL BWP and an UL BWP from a set ofconfigured DL BWPs and UL BWPs; a DCI detection to a PDSCH receptiontiming; a PDSCH reception to a HARQ-ACK transmission timing value; a DCIdetection to a PUSCH transmission timing value; and/or an offset of afirst PRB of a DL bandwidth or an UL bandwidth, respectively, relativeto a first PRB of a bandwidth.

For a DL BWP in a set of one or more DL BWPs on a PCell, a base stationmay configure a wireless device with one or more control resource setsfor at least one type of common search space and/or one wirelessdevice-specific search space. A base station may not configure awireless device without a common search space on a PCell, or on aPSCell, in an active DL BWP. For an UL BWP in a set of one or more ULBWPs, a base station may configure a wireless device with one or moreresource sets for one or more PUCCH transmissions.

DCI may comprise a BWP indicator field. The BWP indicator field valuemay indicate an active DL BWP, from a configured DL BWP set, for one ormore DL receptions. The BWP indicator field value may indicate an activeUL BWP, from a configured UL BWP set, for one or more UL transmissions.

For a PCell, a base station may semi-statically configure a wirelessdevice with a default DL BWP among configured DL BWPs. If a wirelessdevice is not provided a default DL BWP, a default BWP may be an initialactive DL BWP.

A base station may configure a wireless device with a timer value for aPCell. A wireless device may start a timer (e.g., a BWP inactivitytimer), for example, if a wireless device detects DCI indicating anactive DL BWP, other than a default DL BWP, for a paired spectrumoperation, and/or if a wireless device detects DCI indicating an activeDL BWP or UL BWP, other than a default DL BWP or UL BWP, for an unpairedspectrum operation. The wireless device may increment the timer by aninterval of a first value (e.g., the first value may be 1 millisecond,0.5 milliseconds, or any other time duration), for example, if thewireless device does not detect DCI at (e.g., during) the interval for apaired spectrum operation or for an unpaired spectrum operation. Thetimer may expire at a time that the timer is equal to the timer value. Awireless device may switch to the default DL BWP from an active DL BWP,for example, if the timer expires.

A base station may semi-statically configure a wireless device with oneor more BWPs. A wireless device may switch an active BWP from a firstBWP to a second BWP, for example, after or in response to receiving DCIindicating the second BWP as an active BWP, and/or after or in responseto an expiry of BWP inactivity timer (e.g., the second BWP may be adefault BWP). FIG. 10 shows an example of three BWPs configured, BWP1(1010 and 1050), BWP2 (1020 and 1040), and BWP3 (1030). BWP2 (1020 and1040) may be a default BWP. BWP1 (1010) may be an initial active BWP. Awireless device may switch an active BWP from BWP1 1010 to BWP2 1020,for example, after or in response to an expiry of the BWP inactivitytimer. A wireless device may switch an active BWP from BWP2 1020 to BWP31030, for example, after or in response to receiving DCI indicating BWP31030 as an active BWP. Switching an active BWP from BWP3 1030 to BWP21040 and/or from BWP2 1040 to BWP1 1050 may be after or in response toreceiving DCI indicating an active BWP, and/or after or in response toan expiry of BWP inactivity timer.

Wireless device procedures on a secondary cell may be same as on aprimary cell using the timer value for the secondary cell and thedefault DL BWP for the secondary cell, for example, if a wireless deviceis configured for a secondary cell with a default DL BWP amongconfigured DL BWPs and a timer value. A wireless device may use anindicated DL BWP and an indicated UL BWP on a secondary cell as arespective first active DL BWP and first active UL BWP on a secondarycell or carrier, for example, if a base station configures a wirelessdevice with a first active DL BWP and a first active UL BWP on asecondary cell or carrier.

FIG. 11A and FIG. 11B show packet flows using a multi connectivity(e.g., dual connectivity, multi connectivity, tight interworking, and/orthe like). FIG. 11A shows an example of a protocol structure of awireless device 110 (e.g., UE) with CA and/or multi connectivity. FIG.11B shows an example of a protocol structure of multiple base stationswith CA and/or multi connectivity. The multiple base stations maycomprise a master node, MN 1130 (e.g., a master node, a master basestation, a master gNB, a master eNB, and/or the like) and a secondarynode, SN 1150 (e.g., a secondary node, a secondary base station, asecondary gNB, a secondary eNB, and/or the like). A master node 1130 anda secondary node 1150 may co-work to communicate with a wireless device110.

If multi connectivity is configured for a wireless device 110, thewireless device 110, which may support multiple reception and/ortransmission functions in an RRC connected state, may be configured toutilize radio resources provided by multiple schedulers of a multiplebase stations. Multiple base stations may be inter-connected via anon-ideal or ideal backhaul (e.g., Xn interface, X2 interface, and/orthe like). A base station involved in multi connectivity for a certainwireless device may perform at least one of two different roles: a basestation may act as a master base station or act as a secondary basestation. In multi connectivity, a wireless device may be connected toone master base station and one or more secondary base stations. Amaster base station (e.g., the MN 1130) may provide a master cell group(MCG) comprising a primary cell and/or one or more secondary cells for awireless device (e.g., the wireless device 110). A secondary basestation (e.g., the SN 1150) may provide a secondary cell group (SCG)comprising a primary secondary cell (PSCell) and/or one or moresecondary cells for a wireless device (e.g., the wireless device 110).

In multi connectivity, a radio protocol architecture that a bearer usesmay depend on how a bearer is setup. Three different types of bearersetup options may be supported: an MCG bearer, an SCG bearer, and/or asplit bearer. A wireless device may receive and/or send (e.g., transmit)packets of an MCG bearer via one or more cells of the MCG. A wirelessdevice may receive and/or send (e.g., transmit) packets of an SCG bearervia one or more cells of an SCG. Multi-connectivity may indicate havingat least one bearer configured to use radio resources provided by thesecondary base station. Multi-connectivity may or may not be configuredand/or implemented.

A wireless device (e.g., wireless device 110) may send (e.g., transmit)and/or receive: packets of an MCG bearer via an SDAP layer (e.g., SDAP1110), a PDCP layer (e.g., NR PDCP 1111), an RLC layer (e.g., MN RLC1114), and a MAC layer (e.g., MN MAC 1118); packets of a split bearervia an SDAP layer (e.g., SDAP 1110), a PDCP layer (e.g., NR PDCP 1112),one of a master or secondary RLC layer (e.g., MN RLC 1115, SN RLC 1116),and one of a master or secondary MAC layer (e.g., MN MAC 1118, SN MAC1119); and/or packets of an SCG bearer via an SDAP layer (e.g., SDAP1110), a PDCP layer (e.g., NR PDCP 1113), an RLC layer (e.g., SN RLC1117), and a MAC layer (e.g., MN MAC 1119).

A master base station (e.g., MN 1130) and/or a secondary base station(e.g., SN 1150) may send (e.g., transmit) and/or receive: packets of anMCG bearer via a master or secondary node SDAP layer (e.g., SDAP 1120,SDAP 1140), a master or secondary node PDCP layer (e.g., NR PDCP 1121,NR PDCP 1142), a master node RLC layer (e.g., MN RLC 1124, MN RLC 1125),and a master node MAC layer (e.g., MN MAC 1128); packets of an SCGbearer via a master or secondary node SDAP layer (e.g., SDAP 1120, SDAP1140), a master or secondary node PDCP layer (e.g., NR PDCP 1122, NRPDCP 1143), a secondary node RLC layer (e.g., SN RLC 1146, SN RLC 1147),and a secondary node MAC layer (e.g., SN MAC 1148); packets of a splitbearer via a master or secondary node SDAP layer (e.g., SDAP 1120, SDAP1140), a master or secondary node PDCP layer (e.g., NR PDCP 1123, NRPDCP 1141), a master or secondary node RLC layer (e.g., MN RLC 1126, SNRLC 1144, SN RLC 1145, MN RLC 1127), and a master or secondary node MAClayer (e.g., MN MAC 1128, SN MAC 1148).

In multi connectivity, a wireless device may configure multiple MACentities, such as one MAC entity (e.g., MN MAC 1118) for a master basestation, and other MAC entities (e.g., SN MAC 1119) for a secondary basestation. In multi-connectivity, a configured set of serving cells for awireless device may comprise two subsets: an MCG comprising servingcells of a master base station, and SCGs comprising serving cells of asecondary base station. For an SCG, one or more of followingconfigurations may be used. At least one cell of an SCG may have aconfigured UL CC and at least one cell of a SCG, named as primarysecondary cell (e.g., PSCell, PCell of SCG, PCell), and may beconfigured with PUCCH resources. If an SCG is configured, there may beat least one SCG bearer or one split bearer. After or upon detection ofa physical layer problem or a RA problem on a PSCell, or a number of NRRLC retransmissions has been reached associated with the SCG, or afteror upon detection of an access problem on a PSCell associated with(e.g., during) a SCG addition or an SCG change: an RRC connectionre-establishment procedure may not be triggered, UL transmissionstowards cells of an SCG may be stopped, a master base station may beinformed by a wireless device of a SCG failure type, a DL data transferover a master base station may be maintained (e.g., for a split bearer).An NR RLC acknowledged mode (AM) bearer may be configured for a splitbearer. A PCell and/or a PSCell may not be de-activated. A PSCell may bechanged with a SCG change procedure (e.g., with security key change anda RACH procedure). A bearer type change between a split bearer and a SCGbearer, and/or simultaneous configuration of a SCG and a split bearer,may or may not be supported.

With respect to interactions between a master base station and asecondary base stations for multi-connectivity, one or more of thefollowing may be used. A master base station and/or a secondary basestation may maintain RRM measurement configurations of a wirelessdevice. A master base station may determine (e.g., based on receivedmeasurement reports, traffic conditions, and/or bearer types) to requesta secondary base station to provide additional resources (e.g., servingcells) for a wireless device. After or upon receiving a request from amaster base station, a secondary base station may create and/or modify acontainer that may result in a configuration of additional serving cellsfor a wireless device (or decide that the secondary base station has noresource available to do so). For a wireless device capabilitycoordination, a master base station may provide (e.g., all or a part of)an AS configuration and wireless device capabilities to a secondary basestation. A master base station and a secondary base station may exchangeinformation about a wireless device configuration such as by using RRCcontainers (e.g., inter-node messages) carried via Xn messages. Asecondary base station may initiate a reconfiguration of the secondarybase station existing serving cells (e.g., PUCCH towards the secondarybase station). A secondary base station may decide which cell is aPSCell within a SCG. A master base station may or may not change contentof RRC configurations provided by a secondary base station. A masterbase station may provide recent (and/or the latest) measurement resultsfor SCG cell(s), for example, if an SCG addition and/or an SCG SCelladdition occurs. A master base station and secondary base stations mayreceive information of SFN and/or subframe offset of each other from anOAM and/or via an Xn interface (e.g., for a purpose of DRX alignmentand/or identification of a measurement gap). Dedicated RRC signaling maybe used for sending required system information of a cell as for CA, forexample, if adding a new SCG SCell, except for an SFN acquired from anMIB of a PSCell of a SCG.

FIG. 12 shows an example of a RA procedure. One or more events maytrigger a RA procedure. For example, one or more events may be at leastone of following: initial access from RRC_IDLE, RRC connectionre-establishment procedure, handover, DL or UL data arrival in (e.g.,during) a state of RRC_CONNECTED (e.g., if UL synchronization status isnon-synchronized), transition from RRC_Inactive, and/or request forother system information. A PDCCH order, a MAC entity, and/or a beamfailure indication may initiate a RA procedure.

A RA procedure may comprise or be one of at least a contention based RAprocedure and/or a contention free RA procedure. A contention based RAprocedure may comprise one or more Msg 1 1220 transmissions, one or moreMsg2 1230 transmissions, one or more Msg3 1240 transmissions, andcontention resolution 1250. A contention free RA procedure may compriseone or more Msg 1 1220 transmissions and one or more Msg2 1230transmissions. One or more of Msg 1 1220, Msg 2 1230, Msg 3 1240, and/orcontention resolution 1250 may be transmitted in the same step. Atwo-step RA procedure, for example, may comprise a first transmission(e.g., Msg A) and a second transmission (e.g., Msg B). The firsttransmission (e.g., Msg A) may comprise transmitting, by a wirelessdevice (e.g., wireless device 110) to a base station (e.g., base station120), one or more messages indicating an equivalent and/or similarcontents of Msg1 1220 and Msg3 1240 of a four-step RA procedure. Thesecond transmission (e.g., Msg B) may comprise transmitting, by the basestation (e.g., base station 120) to a wireless device (e.g., wirelessdevice 110) after or in response to the first message, one or moremessages indicating an equivalent and/or similar content of Msg2 1230and contention resolution 1250 of a four-step RA procedure.

A base station may send (e.g., transmit, unicast, multicast, broadcast,etc.), to a wireless device, a RACH configuration 1210 via one or morebeams. The RACH configuration 1210 may comprise one or more parametersindicating at least one of following: an available set of PRACHresources for a transmission of a random access preamble (RAP), initialpreamble power (e.g., RAP initial received target power), an RSRPthreshold for a selection of a SS block and corresponding PRACHresource, a power-ramping factor (e.g., RAP power ramping step), a RAPindex, a maximum number of preamble transmissions, preamble group A andgroup B, a threshold (e.g., message size) to determine the groups ofRAPs, a set of one or more RAPs for a system information request andcorresponding PRACH resource(s) (e.g., if any), a set of one or moreRAPs for a beam failure recovery request and corresponding PRACHresource(s) (e.g., if any), a time window to monitor RAR(s), a timewindow to monitor response(s) on a beam failure recovery request, and/ora contention resolution timer.

The Msg1 1220 may comprise one or more transmissions of a RAP. For acontention based RA procedure, a wireless device may select an SS blockwith an RSRP above the RSRP threshold. If RAPs group B exists, awireless device may select one or more RAPs from a group A or a group B,for example, depending on a potential Msg3 1240 size. If a RAPs group Bdoes not exist, a wireless device may select the one or more RAPs from agroup A. A wireless device may select a RAP index randomly (e.g., withequal probability or a normal distribution) from one or more RAPsassociated with a selected group. If a base station semi-staticallyconfigures a wireless device with an association between RAPs and SSblocks, the wireless device may select a RAP index randomly with equalprobability from one or more RAPs associated with a selected SS blockand a selected group.

A wireless device may initiate a contention free RA procedure, forexample, based on a beam failure indication from a lower layer. A basestation may semi-statically configure a wireless device with one or morecontention free PRACH resources for a beam failure recovery requestassociated with at least one of SS blocks and/or CSI-RSs. A wirelessdevice may select a RAP index corresponding to a selected SS block or aCSI-RS from a set of one or more RAPs for a beam failure recoveryrequest, for example, if at least one of the SS blocks with an RSRPabove a first RSRP threshold among associated SS blocks is available,and/or if at least one of CSI-RSs with a RSRP above a second RSRPthreshold among associated CSI-RSs is available.

A wireless device may receive, from a base station, a RAP index viaPDCCH or RRC for a contention free RA procedure. The wireless device mayselect a RAP index, for example, if a base station does not configure awireless device with at least one contention free PRACH resourceassociated with SS blocks or CSI-RS. The wireless device may select theat least one SS block and/or select a RAP corresponding to the at leastone SS block, for example, if a base station configures the wirelessdevice with one or more contention free PRACH resources associated withSS blocks and/or if at least one SS block with a RSRP above a first RSRPthreshold among associated SS blocks is available. The wireless devicemay select the at least one CSI-RS and/or select a RAP corresponding tothe at least one CSI-RS, for example, if a base station configures awireless device with one or more contention free PRACH resourcesassociated with CSI-RSs and/or if at least one CSI-RS with a RSRP abovea second RSPR threshold among the associated CSI-RSs is available.

A wireless device may perform one or more Msg1 1220 transmissions, forexample, by sending (e.g., transmitting) the selected RAP. The wirelessdevice may determine a PRACH occasion from one or more PRACH occasionscorresponding to a selected SS block, for example, if the wirelessdevice selects an SS block and is configured with an association betweenone or more PRACH occasions and/or one or more SS blocks. The wirelessdevice may determine a PRACH occasion from one or more PRACH occasionscorresponding to a selected CSI-RS, for example, if the wireless deviceselects a CSI-RS and is configured with an association between one ormore PRACH occasions and one or more CSI-RSs. The wireless device maysend (e.g., transmit), to a base station, a selected RAP via a selectedPRACH occasions. The wireless device may determine a transmit power fora transmission of a selected RAP at least based on an initial preamblepower and a power-ramping factor. The wireless device may determine anRA-RNTI associated with a selected PRACH occasion in which a selectedRAP is sent (e.g., transmitted). The wireless device may not determinean RA-RNTI for a beam failure recovery request. The wireless device maydetermine an RA-RNTI at least based on an index of a first OFDM symbol,an index of a first slot of a selected PRACH occasions, and/or an uplinkcarrier index for a transmission of Msg1 1220.

A wireless device may receive, from a base station, a RAR, Msg 2 1230.The wireless device may start a time window (e.g., ra-ResponseWindow) tomonitor a RAR. For a beam failure recovery procedure, the base stationmay configure the wireless device with a different time window (e.g.,bfr-ResponseWindow) to monitor response to on a beam failure recoveryrequest. The wireless device may start a time window (e.g.,ra-ResponseWindow or bfr-ResponseWindow) at a start of a first PDCCHoccasion, for example, after a fixed duration of one or more symbolsfrom an end of a preamble transmission. If the wireless device sends(e.g., transmits) multiple preambles, the wireless device may start atime window at a start of a first PDCCH occasion after a fixed durationof one or more symbols from an end of a first preamble transmission. Thewireless device may monitor a PDCCH of a cell for at least one RARidentified by a RA-RNTI, or for at least one response to a beam failurerecovery request identified by a C-RNTI, at a time that a timer for atime window is running.

A wireless device may determine that a reception of RAR is successful,for example, if at least one RAR comprises a random access preambleidentifier (RAPID) corresponding to a RAP sent (e.g., transmitted) bythe wireless device. The wireless device may determine that thecontention free RA procedure is successfully completed, for example, ifa reception of a RAR is successful. The wireless device may determinethat a contention free RA procedure is successfully complete, forexample, if a contention free RA procedure is triggered for a beamfailure recovery request and if a PDCCH transmission is addressed to aC-RNTI. The wireless device may determine that the RA procedure issuccessfully completed, and may indicate a reception of anacknowledgement for a system information request to upper layers, forexample, if at least one RAR comprises a RAPID. The wireless device maystop sending (e.g., transmitting) remaining preambles (if any) after orin response to a successful reception of a corresponding RAR, forexample, if the wireless device has signaled multiple preambletransmissions.

The wireless device may perform one or more Msg 3 1240 transmissions,for example, after or in response to a successful reception of RAR(e.g., for a contention based RA procedure). The wireless device mayadjust an uplink transmission timing, for example, based on a timingadvanced command indicated by a RAR. The wireless device may send (e.g.,transmit) one or more TBs, for example, based on an uplink grantindicated by a RAR. Subcarrier spacing for PUSCH transmission for Msg31240 may be provided by at least one higher layer (e.g., RRC) parameter.The wireless device may send (e.g., transmit) a RAP via a PRACH, andMsg3 1240 via PUSCH, on the same cell. A base station may indicate an ULBWP for a PUSCH transmission of Msg3 1240 via system information block.The wireless device may use HARQ for a retransmission of Msg 3 1240.

Multiple wireless devices may perform Msg 1 1220, for example, bysending (e.g., transmitting) the same preamble to a base station. Themultiple wireless devices may receive, from the base station, the sameRAR comprising an identity (e.g., TC-RNTI). Contention resolution (e.g.,comprising the wireless device 110 receiving contention resolution 1250)may be used to increase the likelihood that a wireless device does notincorrectly use an identity of another wireless device. The contentionresolution 1250 may be based on, for example, a C-RNTI on a PDCCH,and/or a wireless device contention resolution identity on a DL-SCH. Ifa base station assigns a C-RNTI to a wireless device, the wirelessdevice may perform contention resolution (e.g., comprising receivingcontention resolution 1250), for example, based on a reception of aPDCCH transmission that is addressed to the C-RNTI. The wireless devicemay determine that contention resolution is successful, and/or that a RAprocedure is successfully completed, for example, after or in responseto detecting a C-RNTI on a PDCCH. If a wireless device has no validC-RNTI, a contention resolution may be addressed by using a TC-RNTI. Ifa MAC PDU is successfully decoded and a MAC PDU comprises a wirelessdevice contention resolution identity MAC CE that matches or otherwisecorresponds with the CCCH SDU sent (e.g., transmitted) in Msg3 1250, thewireless device may determine that the contention resolution (e.g.,comprising contention resolution 1250) is successful and/or the wirelessdevice may determine that the RA procedure is successfully completed.

RA procedures may be used to establish communications between a wirelessdevice and a base station associated with a cell. A four-step RAprocedure (e.g., such as shown in FIG. 12 and described above) may havean associated latency. The associated latency for the four-step RAprocedure may be a minimum of a quantity (e.g., fourteen or any otherquantity) of transmission time intervals (TTIs). A TTI may be anytransmission time interval or other time duration. A minimum latency offourteen TTIs may comprise, for example, three TTIs after a message fromstep 1 1220 of a four-step RA procedure, one TTI for a message from step2 1230 of a four-step RA procedure, five TTIs after the message fromstep 2, one TTI for a message from step 3 1240 of a four-step RAprocedure, three TTIs after the message from step 3, and one TTI for amessage from step 4 1250 of a four-step procedure (e.g.,3+1+5+1+3+1=14). The minimum latency may comprise any quantity of TTIs.Any of the above-references messages may comprise any quantity of TTIs.Reducing the number of steps in an RA procedure may reduce latency. Afour-step RA procedure may be reduced to a two-step RA procedure, forexample, by using parallel transmissions. A two-step RA procedure mayhave an associated latency. The associated latency for a two-step RAprocedure may be a minimum of four TTIs and which may be less than anassociated latency for a four-step RA procedure. A minimum latency offour TTIs may be a minimum of a quantity (e.g., four or any otherquantity) of TTIs. A minimum latency of four TTIs may comprise, forexample, three TTIs after a message from step 1 of a two-step RAprocedure, and one TTI for a message from step 2 of a two-step RAprocedure.

FIG. 13 shows an example structure for MAC entities. A wireless devicemay be configured to operate in a multi-connectivity mode. A wirelessdevice in RRC_CONNECTED with multiple Rx/Tx may be configured to utilizeradio resources provided by multiple schedulers that may be located in aplurality of base stations. The plurality of base stations may beconnected via a non-ideal or ideal backhaul over the Xn interface. Abase station in a plurality of base stations may act as a master basestation or as a secondary base station. A wireless device may beconnected to and/or in communication with, for example, one master basestation and one or more secondary base stations. A wireless device maybe configured with multiple MAC entities, for example, one MAC entityfor a master base station, and one or more other MAC entities forsecondary base station(s). A configured set of serving cells for awireless device may comprise two subsets: an MCG comprising servingcells of a master base station, and one or more SCGs comprising servingcells of a secondary base station(s). FIG. 13 shows an example structurefor MAC entities in which a MCG and a SCG are configured for a wirelessdevice.

At least one cell in a SCG may have a configured UL CC. A cell of the atleast one cell may comprise a PSCell or a PCell of a SCG, or a PCell. APSCell may be configured with PUCCH resources. There may be at least oneSCG bearer, or one split bearer, for a SCG that is configured. After orupon detection of a physical layer problem or a RA problem on a PSCell,after or upon reaching a number of RLC retransmissions associated withthe SCG, and/or after or upon detection of an access problem on a PSCellassociated with (e.g., during) a SCG addition or a SCG change: an RRCconnection re-establishment procedure may not be triggered, ULtransmissions towards cells of a SCG may be stopped, and/or a masterbase station may be informed by a wireless device of a SCG failure typeand DL data transfer over a master base station may be maintained.

A MAC sublayer may provide services such as data transfer and radioresource allocation to upper layers (e.g., 1310 or 1320). A MAC sublayermay comprise a plurality of MAC entities (e.g., 1350 and 1360). A MACsublayer may provide data transfer services on logical channels. Toaccommodate different kinds of data transfer services, multiple types oflogical channels may be defined. A logical channel may support transferof a particular type of information. A logical channel type may bedefined by what type of information (e.g., control or data) istransferred. BCCH, PCCH, CCCH and/or DCCH may be control channels, andDTCH may be a traffic channel. A first MAC entity (e.g., 1310) mayprovide services on PCCH, BCCH, CCCH, DCCH, DTCH, and/or MAC controlelements. A second MAC entity (e.g., 1320) may provide services on BCCH,DCCH, DTCH, and/or MAC control elements.

A MAC sublayer may expect from a physical layer (e.g., 1330 or 1340)services such as data transfer services, signaling of HARQ feedback,and/or signaling of scheduling request or measurements (e.g., CQI). Indual connectivity, two MAC entities may be configured for a wirelessdevice: one for a MCG and one for a SCG. A MAC entity of a wirelessdevice may handle a plurality of transport channels. A first MAC entitymay handle first transport channels comprising a PCCH of a MCG, a firstBCH of the MCG, one or more first DL-SCHs of the MCG, one or more firstUL-SCHs of the MCG, and/or one or more first RACHs of the MCG. A secondMAC entity may handle second transport channels comprising a second BCHof a SCG, one or more second DL-SCHs of the SCG, one or more secondUL-SCHs of the SCG, and/or one or more second RACHs of the SCG.

If a MAC entity is configured with one or more SCells, there may bemultiple DL-SCHs, multiple UL-SCHs, and/or multiple RACHs per MACentity. There may be one DL-SCH and/or one UL-SCH on an SpCell. Theremay be one DL-SCH, zero or one UL-SCH, and/or zero or one RACH for anSCell. A DL-SCH may support receptions using different numerologiesand/or TTI duration within a MAC entity. A UL-SCH may supporttransmissions using different numerologies and/or TTI duration withinthe MAC entity.

A MAC sublayer may support different functions. The MAC sublayer maycontrol these functions with a control (e.g., Control 1355 and/orControl 1365) element. Functions performed by a MAC entity may compriseone or more of: mapping between logical channels and transport channels(e.g., in uplink or downlink), multiplexing (e.g., (De-) Multiplexing1352 and/or (De-) Multiplexing 1362) of MAC SDUs from one or differentlogical channels onto TBs to be delivered to the physical layer ontransport channels (e.g., in uplink), demultiplexing (e.g., (De-)Multiplexing 1352 and/or (De-) Multiplexing 1362) of MAC SDUs to one ordifferent logical channels from TBs delivered from the physical layer ontransport channels (e.g., in downlink), scheduling information reporting(e.g., in uplink), error correction through HARQ in uplink and/ordownlink (e.g., 1363), and logical channel prioritization in uplink(e.g., Logical Channel Prioritization 1351 and/or Logical ChannelPrioritization 1361). A MAC entity may handle a RA process (e.g., RandomAccess Control 1354 and/or Random Access Control 1364).

FIG. 14 shows an example of a RAN architecture comprising one or morebase stations. A protocol stack (e.g., RRC, SDAP, PDCP, RLC, MAC, and/orPHY) may be supported at a node. A base station (e.g., gNB 120A and/or120B) may comprise a base station central unit (CU) (e.g., gNB-CU 1420Aor 1420B) and at least one base station distributed unit (DU) (e.g.,gNB-DU 1430A, 1430B, 1430C, and/or 1430D), for example, if a functionalsplit is configured. Upper protocol layers of a base station may belocated in a base station CU, and lower layers of the base station maybe located in the base station DUs. An F1 interface (e.g., CU-DUinterface) connecting a base station CU and base station DUs may be anideal or non-ideal backhaul. F1-C may provide a control plane connectionover an F1 interface, and F1-U may provide a user plane connection overthe F1 interface. An Xn interface may be configured between base stationCUs.

A base station CU may comprise an RRC function, an SDAP layer, and/or aPDCP layer. Base station DUs may comprise an RLC layer, a MAC layer,and/or a PHY layer. Various functional split options between a basestation CU and base station DUs may be possible, for example, bylocating different combinations of upper protocol layers (e.g., RANfunctions) in a base station CU and different combinations of lowerprotocol layers (e.g., RAN functions) in base station DUs. A functionalsplit may support flexibility to move protocol layers between a basestation CU and base station DUs, for example, depending on servicerequirements and/or network environments.

Functional split options may be configured per base station, per basestation CU, per base station DU, per wireless device, per bearer, perslice, and/or with other granularities. In a per base station CU split,a base station CU may have a fixed split option, and base station DUsmay be configured to match a split option of a base station CU. In a perbase station DU split, a base station DU may be configured with adifferent split option, and a base station CU may provide differentsplit options for different base station DUs. In a per wireless devicesplit, a base station (e.g., a base station CU and at least one basestation DUs) may provide different split options for different wirelessdevices. In a per bearer split, different split options may be utilizedfor different bearers. In a per slice splice, different split optionsmay be used for different slices.

FIG. 15 shows example RRC state transitions of a wireless device. Awireless device may be in at least one RRC state among an RRC connectedstate (e.g., RRC Connected 1530, RRC_Connected, etc.), an RRC idle state(e.g., RRC Idle 1510, RRC_Idle, etc.), and/or an RRC inactive state(e.g., RRC Inactive 1520, RRC_Inactive, etc.). In an RRC connectedstate, a wireless device may have at least one RRC connection with atleast one base station (e.g., gNB and/or eNB), which may have a contextof the wireless device (e.g., UE context). A wireless device context(e.g., UE context) may comprise at least one of an access stratumcontext, one or more radio link configuration parameters, bearer (e.g.,data radio bearer (DRB), signaling radio bearer (SRB), logical channel,QoS flow, PDU session, and/or the like) configuration information,security information, PHY/MAC/RLC/PDCP/SDAP layer configurationinformation, and/or the like configuration information for a wirelessdevice. In an RRC idle state, a wireless device may not have an RRCconnection with a base station, and a context of the wireless device maynot be stored in a base station. In an RRC inactive state, a wirelessdevice may not have an RRC connection with a base station. A context ofa wireless device may be stored in a base station, which may comprise ananchor base station (e.g., a last serving base station).

A wireless device may transition an RRC state (e.g., UE RRC state)between an RRC idle state and an RRC connected state in both ways (e.g.,connection release 1540 or connection establishment 1550; and/orconnection reestablishment) and/or between an RRC inactive state and anRRC connected state in both ways (e.g., connection inactivation 1570 orconnection resume 1580). A wireless device may transition its RRC statefrom an RRC inactive state to an RRC idle state (e.g., connectionrelease 1560).

An anchor base station may be a base station that may keep a context ofa wireless device (e.g., UE context) at least at (e.g., during) a timeperiod that the wireless device stays in a RAN notification area (RNA)of an anchor base station, and/or at (e.g., during) a time period thatthe wireless device stays in an RRC inactive state. An anchor basestation may comprise a base station that a wireless device in an RRCinactive state was most recently connected to in a latest RRC connectedstate, and/or a base station in which a wireless device most recentlyperformed an RNA update procedure. An RNA may comprise one or more cellsoperated by one or more base stations. A base station may belong to oneor more RNAs. A cell may belong to one or more RNAs.

A wireless device may transition, in a base station, an RRC state (e.g.,UE RRC state) from an RRC connected state to an RRC inactive state. Thewireless device may receive RNA information from the base station. RNAinformation may comprise at least one of an RNA identifier, one or morecell identifiers of one or more cells of an RNA, a base stationidentifier, an IP address of the base station, an AS context identifierof the wireless device, a resume identifier, and/or the like.

An anchor base station may broadcast a message (e.g., RAN pagingmessage) to base stations of an RNA to reach to a wireless device in anRRC inactive state. The base stations receiving the message from theanchor base station may broadcast and/or multicast another message(e.g., paging message) to wireless devices in their coverage area, cellcoverage area, and/or beam coverage area associated with the RNA via anair interface.

A wireless device may perform an RNA update (RNAU) procedure, forexample, if the wireless device is in an RRC inactive state and movesinto a new RNA. The RNAU procedure may comprise a RA procedure by thewireless device and/or a context retrieve procedure (e.g., UE contextretrieve). A context retrieve procedure may comprise: receiving, by abase station from a wireless device, a RAP; and requesting and/orreceiving (e.g., fetching), by a base station, a context of the wirelessdevice (e.g., UE context) from an old anchor base station. Therequesting and/or receiving (e.g., fetching) may comprise: sending aretrieve context request message (e.g., UE context request message)comprising a resume identifier to the old anchor base station andreceiving a retrieve context response message comprising the context ofthe wireless device from the old anchor base station.

A wireless device in an RRC inactive state may select a cell to camp onbased on at least a measurement result for one or more cells, a cell inwhich a wireless device may monitor an RNA paging message, and/or a corenetwork paging message from a base station. A wireless device in an RRCinactive state may select a cell to perform a RA procedure to resume anRRC connection and/or to send (e.g., transmit) one or more packets to abase station (e.g., to a network). The wireless device may initiate a RAprocedure to perform an RNA update procedure, for example, if a cellselected belongs to a different RNA from an RNA for the wireless devicein an RRC inactive state. The wireless device may initiate a RAprocedure to send (e.g., transmit) one or more packets to a base stationof a cell that the wireless device selects, for example, if the wirelessdevice is in an RRC inactive state and has one or more packets (e.g., ina buffer) to send (e.g., transmit) to a network. A RA procedure may beperformed with two messages (e.g., 2-stage or 2-step random access)and/or four messages (e.g., 4-stage or 4-step random access) between thewireless device and the base station.

A base station receiving one or more uplink packets from a wirelessdevice in an RRC inactive state may request and/or receive (e.g., fetch)a context of a wireless device (e.g., UE context), for example, bysending (e.g., transmitting) a retrieve context request message for thewireless device to an anchor base station of the wireless device basedon at least one of an AS context identifier, an RNA identifier, a basestation identifier, a resume identifier, and/or a cell identifierreceived from the wireless device. A base station may send (e.g.,transmit) a path switch request for a wireless device to a core networkentity (e.g., AMF, MME, and/or the like), for example, after or inresponse to requesting and/or receiving (e.g., fetching) a context. Acore network entity may update a downlink tunnel endpoint identifier forone or more bearers established for the wireless device between a userplane core network entity (e.g., UPF, S-GW, and/or the like) and a RANnode (e.g., the base station), such as by changing a downlink tunnelendpoint identifier from an address of the anchor base station to anaddress of the base station).

A base station may communicate with a wireless device via a wirelessnetwork using one or more technologies, such as new radio technologies(e.g., NR, 5G, etc.). The one or more radio technologies may comprise atleast one of: multiple technologies related to physical layer; multipletechnologies related to medium access control layer; and/or multipletechnologies related to radio resource control layer Enhancing the oneor more radio technologies may improve performance of a wirelessnetwork. System throughput, and/or data rate of transmission, may beincreased. Battery consumption of a wireless device may be reduced.Latency of data transmission between a base station and a wirelessdevice may be improved. Network coverage of a wireless network may beimproved. Transmission efficiency of a wireless network may be improved.

Wireless communications may comprise search procedures. A wirelessdevice may perform a search procedure, for example, to determine a cellfor communicating with a base station. A wireless device may perform acell search. The wireless device may acquire time and frequencysynchronization with a cell. The wireless device may detect a firstphysical layer cell ID of the cell, for example, during the cell searchprocedure. The wireless device may perform the cell search, for example,if the wireless device has received one or more synchronization signals(SS) (e.g., comprising the PSS and the SSS). The wireless device mayassume/determine that reception occasions of one or more of a PBCH, aPSS, and/or an SSS are in consecutive symbols. The wireless device mayassume/determine that reception occasions of one or more of PBCH, PSS,and/or SSS correspond to an SSB, for example, based on being inconsecutive symbols. A wireless device may assume/determine that an SSS,a PBCH demodulation reference signal (DM-RS), and/or PBCH data have thesame (or similar) energy per resource element (EPRE). A wireless devicemay assume/determine that the ratio of PSS EPRE to SSS EPRE in anSS/PBCH block is a particular value (e.g., either 0 dB, 3 dB, or anyother value). A wireless device may assume/determine that the ratio ofPDCCH DM-RS EPRE to SSS EPRE is within a particular range (e.g., from −8dB to 8 dB, or any other range), for example, if the wireless device hasnot received dedicated higher layer parameters.

A wireless device may determine a first symbol index for one or morecandidate SS/PBCH blocks (SSBs). The first symbol index for one or morecandidate SSBs may be determined according to a subcarrier spacing ofthe SSBs, for example, for a half frame with SSBs. Index 0 maycorrespond to the first symbol of the first slot in a half frame. Thefirst symbol of the one or more candidate SSBs may have indexes {2,8}+14·n for 15 kHz subcarrier spacing, where, for example, n=0, 1 forcarrier frequencies smaller than or equal to 3 GHz (or any otherfrequency), and for example, n=0,1, 2, 3 for carrier frequencies largerthan 3 GHz and smaller than or equal to 6 GHz (or any other frequency).For example, n may be an index indicating a numerology configured at thecarrier frequencies. The one or more candidate SSBs in a half frame maybe indexed in an ascending order in time, for example, from 0 to L−1.The wireless device may determine some bits (for example, two leastsignificant bits (LSB) for L=4, three LSB bits for L>4, or any otherquantity of bits) of an SSB index per half frame from, for example, aone-to-one mapping with one or more indexes of a DM-RS sequencetransmitted in the PBCH.

Access procedures (e.g., random access (RA) procedures) may be used toestablish communications between a wireless device and a base station ina cell. Prior to initiation of a random access procedure, a base stationmay send (e.g., transmit) one or more RRC messages to configure thewireless device with one or more parameters of a RACH configuration. Theone or more RRC messages may be broadcasted and/or multicasted to one ormore wireless devices. The one or more RRC messages may be wirelessdevice-specific messages (e.g., a dedicated RRC messages transmitted toa wireless device with RRC INACTIVE 1520 or RRC CONNECTED 1530). The oneor more RRC messages may comprise one or more parameters fortransmitting at least one preamble via one or more random accessresources. The one or more parameters may indicate at least one of thefollowing: a PRACH resource allocation, a preamble format, SSBinformation (e.g., total number/quantity of SSBs, downlink resourceallocation of SSB transmission, a transmission power of SSBtransmission, and/or other information), and/or uplink radio resourcesfor one or more transport block transmissions.

A base station may send/transmit one or more downlink reference signals.The one or more downlink reference signals may comprise one or morediscovery reference signals. A wireless device may determine/select afirst downlink reference signal among the one or more downlink referencesignals. The first downlink reference signal may comprise one or moreSSBs. A wireless device may determine/adjust/change a downlinksynchronization based on the one or more synchronization signals. Theone or more downlink reference signals may comprise one or more CSI-RSs.

The one or more RRC messages may comprise one or more parametersindicating one or more downlink control channels (e.g., PDDCH). Each ofthe one or more downlink control channels may be associated with atleast one of the one or more downlink reference signals. The firstdownlink reference signal may comprise system information (e.g., masterinformation block (MIB) and/or system information block (SIB)). A basestation may send/transmit the system information, for example, via thePBCH, PDCCH, and/or PDSCH.

A wireless device (e.g., MAC entity of a wireless device) maydetermine/select one or more random access resources for a random accessprocedure. The wireless device (e.g., MAC entity of the wireless device)may determine/select a first downlink reference signal. The wirelessdevice (e.g., MAC entity of the wireless device) may determine/selectthe first downlink reference signal (e.g., a first SSB or a firstCSI-RS) with the first reference signal received power (RSRP) above afirst RSRP threshold. The first RSRP threshold may be determined/definedbased on a type of reference signal (e.g., rsrp-ThresholdSSB may be foran SSB, and rsrp-ThresholdCSI-RS for a CSI-RS). The first RSRP thresholdmay be broadcasted, semi-statically configured, and/or predefined. Thewireless device (e.g., a MAC entity of the wireless device) maydetermine/select the first downlink reference signal for acontention-free random access procedure, for example, for beam failurerecovery or a system information request. The wireless device (e. g., aMAC entity of the wireless device) may determine/select the firstdownlink reference signal for a contention-based random accessprocedure.

A wireless device may select one or more random access resources. Theone or more random access resources may comprise one or more randomaccess preambles, one or more time resources, and/or one or morefrequency resources for PRACH transmission. The one or more randomaccess resources may be predefined. The one or more random accessresources may be configured/indicated/provided by one or more RRCmessages. The one or more random access resources may beconfigured/indicated/provided by one or more downlink control orders(e.g., a PDCCH order). The one or more random access resources may bedetermined based on the first downlink reference signal. A wirelessdevice may set a first preamble index to a parameter (e.g.,ra-PreambleIndex) corresponding to the first downlink reference signal.

A wireless device may send/transmit at least one random access preamblevia the one or more random access resources. A wireless device maysend/transmit a first preamble with the first preamble index. The firstpreamble may be sent/transmitted using a first PRACH format with a firsttransmission power via one or more PRACH resources. The one or morePRACH resources may comprise one or more PRACH occasions.

A base station may configure a wireless device with a serving cellcomprising one or more channels (e.g., BWPs, sub-bands, etc.). A maximumquantity/number (e.g., 3, 4, etc.) of BWP (or other wireless resources)per a serving cell may be predefined. A base station may send/transmit amessage (or a control signal) indicating BWP switching between two BWPs.

A serving cell may be configured with one or multiple BWPs, a maximumnumber of BWP per serving cell may be a first number. BWP switching fora serving cell may be used to activate an inactive BWP and deactivate anactive BWP at a determined time. BWP switching may be controlled by aPDCCH message (e.g., signal) indicating a downlink assignment or anuplink grant (e.g., by the bwp-InactivityTimer, by RRC signalling, or bythe wireless device (e.g., MAC entity of the wireless device) itselfupon initiation of RA procedure). The DL BWP and UL BWP indicated by afirst active downlink BWP identifier (e.g., firstActiveDownlinkBWP-Id)and a first active uplink BWP identifier (e.g., firstActiveUplinkBWP-Id)respectively may be active without receiving a message (e.g., signal)via PDCCH indicating a downlink assignment or an uplink grant, forexample, based on or in response to addition of an SpCell or activationof an SCell. The active BWP for a serving cell may be indicated byeither an RRC message or PDCCH message (e.g., signal). A DL BWP may bepaired with a UL BWP, and BWP switching may be common for both UL andDL, for example, based on an unpaired spectrum.

The wireless device (e.g., MAC entity of the wireless device) may switchthe active UL BWP to BWP indicated by an initial uplink BWP parameter(e.g., initialUplinkBWP), for example, based on or in response toinitiation of the RA procedure on a serving cell and/or, PRACH occasionsnot being configured for the active UL BWP. The wireless device (e.g.,MAC entity of the wireless device) may switch the active DL BWP to BWPindicated by an initial downlink BWP parameter (e.g.,initialDownlinkBWP), for example, based on the serving cell being aSpCell. The wireless device (e.g., MAC entity of the wireless device)may perform the RA procedure on the active DL BWP of SpCell and activeUL BWP of this serving cell.

The wireless device (e.g., MAC entity of the wireless device) may switchthe active DL BWP to the DL BWP with the same BWP index (e.g., bwp-Id)as the active UL BWP, for example, based on or in response to initiationof the RA procedure on a serving cell, the PRACH occasions beingconfigured for the active UL BWP, the serving cell is a SpCell, and/orif the active DL BWP does not have the same BWP index (e.g., bwp-Id) asthe active UL BWP. The wireless device (e.g., MAC entity of the wirelessdevice) may perform the RA procedure on the active DL BWP of SpCell andactive UL BWP of this serving cell.

A wireless device may determine whether to switch BWP or ignore thePDCCH message for BWP switching, for example, based on the wirelessdevice (e.g., MAC entity of the wireless device) receiving a PDCCHmessage for BWP switching for a serving cell while a RA procedureassociated with that serving cell is ongoing in the wireless device(e.g., MAC entity of the wireless device). The wireless device mayperform BWP switching to a BWP indicated by the PDCCH message, forexample, based on the PDCCH reception for BWP switching addressed to theC-RNTI for successful RA procedure completion. The wireless device(e.g., MAC entity of the wireless device) may stop the ongoing RAprocedure and may initiate a RA procedure on the new activated BWP, forexample, based on or in response to reception of the PDCCH message forBWP switching other than successful contention resolution, and/or thewireless device (e.g., MAC entity of the wireless device) deciding toperform BWP switching. The wireless device (e.g., MAC entity of thewireless device) may continue with the ongoing RA procedure on theactive BWP, for example, based on the wireless device deciding to ignorethe PDCCH message for BWP switching.

A wireless device, configured for operation in BWPs of a serving cell,may be configured by higher layers for the serving cell a set of at mosta first threshold value (e.g., 4, 8, 16, 32 or any other quantity) ofBWPs for reception by the wireless device in a DL bandwidth (e.g., a DLBWP set) by a BWP downlink parameter (e.g., BWP-Downlink) and a set ofat most a second threshold value (e.g., 4, 8, 16, 32 or any otherquantity) BWPs for transmissions by the wireless device in an ULbandwidth (e.g., a UL BWP set) by a BWP uplink parameter (e.g.,BWP-Uplink) for the serving cell.

An initial active DL BWP may be defined by a location and number ofcontiguous PRBs, a subcarrier spacing, and a cyclic prefix, for thecontrol resource set for a downlink common search space (e.g.,TypeO-PDCCH common search space). A wireless device may be provided(e.g., configured with, indicated by, etc.) an initial active UL BWP bya higher layer initial uplink BWP parameter (e.g., initialuplinkBWP) forexample, for operation on the primary cell or on a secondary cell. Thewireless device may be provided (e.g., configured with, indicated by,etc.) an initial UL BWP on the supplementary carrier by a higher layerinitial uplink BWP parameter (e.g., initialUplinkBWP) in a supplementaryuplink, for example, based on the wireless device being configured witha supplementary carrier (SUL).

The wireless device may be configured with the following parameters forthe serving cell for each DL BWP or UL BWP in a set of DL BWPs or ULBWPs, respectively: a subcarrier spacing provided by (e.g., configuredby, stored in, indicated by, etc.) a parameter (e.g., a higher layerparameter such as, for example, subcarrierSpacing); a cyclic prefixprovided by (e.g., configured by, stored in, indicated by, etc.) aparameter (e.g., a higher layer parameter such as, for example,cyclicPrefix); a first PRB and a number of contiguous PRBs indicated bya parameter (e.g., a higher layer parameter such as, for example,locationAndBandwidth) that may be interpreted as RIV, setting N_(BWP)^(size)=275, and the first PRB being a PRB offset relative to the PRBindicated by parameters (e.g., a higher layer parameter such as, forexample, offsetToCarrier and subcarrierSpacing); an index in the set ofDL BWPs or UL BWPs via a parameter (e.g., a higher layer parameter suchas, for example, bwp-Id); and/or a set of BWP-common and a set ofBWP-dedicated parameters via parameters (e.g., a higher layer parametersuch as, for example, bwp-Common and bwp-Dedicated).

A DL BWP from the set of configured DL BWPs with index provided by(e.g., configured by, indicated by, etc.) higher layer BWP indexparameter (e.g., bwp-Id) for the DL BWP is linked with an UL BWP fromthe set of configured UL BWPs with index provided (e.g., configured by,indicated by, etc.) by higher layer BWP index parameter (e.g., bwp-Id)for the UL BWP if the DL BWP index and the UL BWP index are equal, forexample, based on unpaired spectrum operation A wireless device may notexpect to receive a configuration where the center frequency for a DLBWP is different than the center frequency for an UL BWP if the BWPindex parameter (bwp-Id) of the DL BWP is equal to the bwp-Id of the ULBWP, for example, based on unpaired spectrum operation.

FIG. 16 shows an example BWP configuration information element (e.g., aBWP IE). A BWP IE may be used to configure a BWP. The network mayconfigure at least an initial BWP comprising at least a downlink BWP andone (e.g., if the serving cell is configured with an uplink) or two(e.g., if using supplementary uplink (SUL)) uplink BWPs, for example,for each serving cell. The network may configure additional uplink anddownlink BWPs for a serving cell.

The BWP configuration may be split into uplink and downlink parametersand/or into common and dedicated parameters. Common parameters (e.g.,BWP-UplinkCommon and BWP-DownlinkCommon) may be cell specific and/or thenetwork may ensure the necessary alignment with corresponding parametersof other wireless devices. Common parameters of the initial BWP of thePCell may be provided via system information. The network may providethe common parameters via dedicated signaling.

A field, IE, or prefix (e.g., cyclic prefix) may indicate whether to usethe extended cyclic prefix for this BWP. The wireless device may use thenormal cyclic prefix (CP), for example, if the CP is not set. Normal CPmay be supported for all numerologies and slot formats. Extended CP maybe supported only for 60 kHz subcarrier spacing (or some other frequencysubcarrier spacing). A parameter (e.g., locationAndBanddwidth) mayindicate a frequency domain location and/or a bandwidth of this BWP. Thevalue of the field may be interpreted as a RIV. A first PRB may be a PRBdetermined by a subcarrier spacing parameter (e.g., subcarrierSpacing)of this BWP and/or an offset parameter (e.g., offsetToCarrier(configured in SCS-SpecificCarrier contained within FrequencyInfoDL))corresponding to this subcarrier spacing. A BWP-pair (e.g., UL BWP andDL BWP with the same index) may have the same center frequency, forexample, based on use of TDD. The subcarrier spacing parameter mayindicate subcarrier spacing to be used in this BWP for channels andreference signals unless explicitly configured elsewhere. The valuekHz15 may correspond to μ=0, kHz30 to μ=1, and so on. The values 15, 30,or 60 kHz may be used. A BWP index (e.g., bwp-Id) may indicate anidentifier for a BWP.

Other parts of the RRC configuration may use the BWP index (e.g.,BWP-Id) to associate with a particular BWP. A particular BWP ID (e.g.,BWP ID=0) may be associated with an initial BWP and/or may not be usedwith other BWPs. The network (NW) (e.g., the base station) may triggerthe wireless device to switch UL or DL BWP using a DCI field. The fourcode points in the DCI field may map to the RRC-configured BWP index(e.g., BWP-Id). The DCI code point may be equivalent to the BWP ID(initial=0, first dedicated=1, . . . ), for example, for up to threeconfigured BWPs (in addition to the initial BWP). The BWPs may beidentified by DCI code points 0 to 3, for example, if the NW configures4 dedicated BWPs. It may not be possible to switch to the initial BWPusing the DCI field, for example, with this configuration. The BWP index(e.g., bwp-Id) may indicate an identifier for a BWP. Other parts of theRRC configuration may use the BWP index (e.g., BWP-Id) to associatethemselves with a particular BWP. A BWP ID=0 may be associated with theinitial BWP and may not be used in other BWPs.

The NW may trigger the wireless device to switch an UL BWP and/or a DLBWP using a DCI field. The four code points in that DCI field may map tothe RRC-configured BWP index (e.g., BWP-ID). The DCI code point may beequivalent to the BWP index (e.g., BWP ID where initial=0, firstdedicated=1, . . . ), for example, for up to three configured BWPs (inaddition to the initial BWP). The BWPs may be identified by DCI codepoints 0 to 3, for example, if the NW configures four dedicated BWPs. Itmay not be possible to switch to the initial BWP using the DCI field,for example, with this configuration. A common random accessconfiguration (e.g., rach-ConfigCommon) may indicate configuration ofcell specific RA parameters that the wireless device may use forcontention based random access, contention free random access, and/orcontention based beam failure recovery. The NW may configure SSB-basedRA (including RACH-ConfigCommon) for UL BWPs, for example, based on thelinked DL BWPs allowing the wireless device to acquire the SSBassociated to the serving cell. An uplink control channel configuration(e.g., PUCCH-config) may indicate an uplink control channelconfiguration (e.g., PUCCH configuration) for one BWP of the regular ULor SUL of a serving cell. The network may configure PUCCH on the BWPs ofone of the uplinks (UL or SUL), for example, if the wireless device isconfigured with SUL.

The network may configure PUCCH-Config for each SpCell. The network mayconfigure one additional SCell of a cell group with an uplink controlchannel configuration (e.g., PUCCH-Config for a PUCCH SCell), forexample, if supported by the wireless device. The IE BWP-Id may be usedto refer to BWP. The initial BWP may be referred to by a zero index(e.g., BWP-Id 0). The other BWPs may be referred to by a non-zero index(e.g., BWP-Id 1 to a maximum number/quantity of BWPs (e.g.,maxNrofBWPs)).

FIG. 17 shows an example serving cell configuration information element.A serving cell configuration (e.g., ServingCellConfig IE) may be used toconfigure (e.g., add or modify) the wireless device with a serving cell.The serving cell may be the SpCell or an SCell of an MCG or SCG. Theparameters of the serving cell configuration may comprise wirelessdevice specific parameters and/or cell specific parameters (e.g.additionally configured BWPs).

A default downlink BWP index (e.g., defaultDownlinkBWP-Id) maycorrespond to a default L1 downlink BWP parameter (e.g.,‘default-DL-BWP’). The initial BWP may be referred to by a BWP index(e.g., BWP-Id=0). The ID of the downlink BWP may be used after timerexpiry. This ID field may be wireless device specific. The wirelessdevice may use the initial BWP as default BWP, for example, if the fieldis absent.

An initial downlink BWP (e.g., InitialDownlinkBWP) may indicate adedicated (e.g., wireless device-specific) configuration for the initialdownlink BWP. A first active uplink BWP identifier (e.g.,FirstActiveUplinkBWP-Id), if configured for an SpCell, may comprise theID of the DL BWP to be activated upon performing the reconfiguration inwhich it is received. The RRC reconfiguration may not impose a BWPswitching (e.g., corresponding to L1 parameter ‘active-BWP-UL-Pcell’),for example, if the field is absent. This field may comprise the ID ofthe uplink BWP to be used upon MAC-activation of an SCell, for example,if configured for an SCell. The initial BWP may be referred to asBandwidthPartId=0. An initial uplink BWP (e.g., InitialUplinkBWP) mayindicate a dedicated (e.g., wireless device-specific) configuration forthe initial uplink BWP.

A wireless device may be configured (e.g., by a base station) with oneor more UL carriers associated with a DL carrier of a cell. One of oneor more UL carriers configured with a DL carrier may be referred to as asupplementary uplink (SUL) carrier or a normal UL (NUL or may bereferred to as a non-SUL) carrier. A base station may enhance ULcoverage and/or capacity by configuring an SUL carrier. A base stationmay configure a BWP configuration per an uplink (e.g., per uplinkcarrier) associated with a cell. One or more BWPs on an SUL may beconfigured (e.g., by a base station) separately from one or more BWPs ona NUL. A base station may control an active BWP of an SUL independentlyof an active BWP of a NUL. A base station may control two or more uplinktransmissions on two or more UL carriers (e.g., NUL and SUL) to avoidoverlapping PUSCH transmissions in time. SUL and/or NUL may beconfigured in an unlicensed band. A wireless device may be configured(e.g., by a base station) with one or more following: an SUL in alicensed band and a NUL in a licensed band; an SUL in a licensed bandand a NUL in an unlicensed band; an SUL in an unlicensed band and a NULin a licensed band; and/or an SUL in an unlicensed band and a NUL in anunlicensed band.

An SUL carrier and a NUL carrier may be configured (e.g., by a basestation) to support a RA procedure (e.g., initial access). Support for aRA to a cell configured with SUL is shown in FIG. 12, described above. ARACH configuration 1210 of an SUL may be configured (e.g., by a basestation) independent of a RACH configuration 1210 of an NUL. One or moreparameters associated with Msg1 1220, Msg 2 1230, Msg 3 1240, and/orcontention resolution 1250 via an SUL may be configured independent ofone or more parameters associated with Msg1 1220, Msg 2 1230, Msg 31240, and/or contention resolution 1250 via an NUL. One or moreparameters associated with PRACH transmissions in Msg 1 1220 via an SULmay be independent of one or more parameters associated with PRACHtransmission via an NUL.

A wireless device may determine which carrier (e.g., between NUL andSUL) to use, for example, based on an RA procedure in an unlicensed bandand/or in a licensed bands and/or based on a measurement (e.g., RSRP) ofone or more DL pathloss references. A wireless device may select a firstcarrier (e.g., SUL or NUL carrier) if a measured quality (e.g., RSRP) ofDL pathloss references is less than a broadcast threshold (e.g., an RRCparameter, rsrp-ThresholdSSB-SUL in RACH-ConfigCommon). One or moreuplink transmissions associated with the RA procedure may remain on theselected carrier, for example, based on a wireless device selecting acarrier between SUL carrier and NUL carrier for an RA procedure.

FIG. 18 shows an example of a coverage of a cell configured with a DLand two UL carriers. A base station 120 may configure a NUL and DL overa first frequency (e.g., high frequency). An SUL may be configured overa second frequency (e.g., low frequency) to support uplink transmission(e.g., in terms of coverage and/or capacity) of a cell. A broadcastthreshold (e.g., an RRC parameter, rsrp-ThresholdSSB-SUL) for a wirelessdevice to select a carrier may be determined such that a wireless devicelocated outside a NUL coverage 1810 but inside an SUL coverage 1820 maystart a RA procedure via an SUL. A wireless device located inside a NULcoverage 1810 may start a RA procedure via a NUL. A wireless device mayuse a RACH configuration associated with a selected carrier for a RAprocedure.

A wireless device may perform a contention based RA procedure and/or acontention free RA procedure. A wireless device may perform a RAprocedure on an UL selected based on a broadcast threshold (e.g.,rsrp-ThresholdSSB-SUL). A base station may not indicate (e.g.,explicitly) to the wireless device which carrier to start a RAprocedure. A base station may indicate which carrier a wireless deviceperforms a RA procedure by sending a RACH configuration with an SULindicator (e.g., 0 may indicates a NUL carrier, 1 may indicate an SULcarrier or vice versa). A base station may indicate (e.g., explicitly)to a wireless device which UL carrier is to be used for a contentionfree or contention based RA procedure. A base station may indicate acontention free RA procedure by sending a RACH configuration with adedicated preamble index. A base station may indicate a contention basedRA procedure by sending a RACH configuration without a dedicatedpreamble index.

A base station may select a carrier between NUL carrier(s) and/or SULcarrier(s), for example, based on the quality of the one or moremeasurements and/or if a wireless device sends quality information ofone or more measurements on one or more DL reference signals associatedwith NUL carrier(s) and/or SUL carrier(s). A base station may indicate,to a wireless device, a selected carrier via RRC signaling (e.g.,handover) and/or PDCCH order (e.g., SCell addition) for initiating a(contention free or contention based) RA procedure. For load balancingbetween NUL carrier(s) and/or SUL carrier(s), a base station may selectone of NUL and SUL carrier by taking into consideration congestion inNUL carrier(s) and/or SUL carrier(s). A base station may better select acarrier (e.g., NUL or SUL) of a target cell for a (contention free orcontention based) RA procedure for a handover, for example, based on oneor more measurement reports associated with NUL carrier(s) and/or SULcarrier(s). A base station may better select a carrier (e.g., NUL orSUL) of an SCell (e.g., if the SCell is configured with at least a NULcarrier and an SUL carrier) for a (contention free or contention based)RA procedure for an SCell addition, for example, based on one or moremeasurement reports associated with NUL carrier(s) and/or SULcarrier(s).

A base station may determine whether SUL carrier(s) is (are) configuredin an SCell, and/or which carrier is allowed to be used for an SCelladdition. A base station may configure DL measurements on NUL carrier(s)and/or SUL carrier(s). A base station may configure a wireless devicewith one or more RACH configurations for an SCell, e.g., a first RACHconfiguration for an SUL carrier, a second RACH configuration for a NULcarrier, and so on. A base station may send (e.g., transmit), to awireless device via a PDCCH order comprising a parameter indicating inwhich carrier the wireless device starts a (contention free orcontention based) RA procedure. A PDCCH order triggering a (contentionfree or contention based) RA procedure may comprise one or moreparameters indicating at least one of at least one preamble (e.g.,preamble index), one or more PRACH resources (e.g., PRACH mask index),an SUL indicator, and/or a BWP indicator. A wireless device receiving aPDCCH order may send (e.g., transmit) at least one preamble via one ormore PRACH resources of a BWP indicated by a BWP indicator of a carrierindicated by an SUL indicator, for example, for a RA procedure.

FIG. 19 shows an example of a two-step RA procedure. The two-step RAprocedure may comprise an uplink (UL) transmission of a two-step Msg11920 that may comprise a random access preamble (RAP) transmission 1930and one or more transport blocks transmission 1940, followed by adownlink (DL) transmission of a two-step Msg2 1950 that may comprise aresponse (e.g., random access response (RAR)) corresponding to theuplink transmission. The response may comprise contention resolutioninformation. The two-step Msg1 1920 may be referred to as a message A(MsgA). The two-step Msg2 1950 may be referred to as a message B (MsgB).

A base station may send/transmit one or more RRC messages to configure awireless device with one or more parameters of two step RACHconfiguration 1910. The one or more RRC messages may be broadcasted,multicasted, and/or unicasted to one or more wireless devices. The oneor more RRC messages may be wireless device-specific messages (e.g., adedicated RRC message transmitted to a wireless device with RRC INACTIVE1520 or RRC CONNECTED 1530). The one or more RRC messages may compriseparameters for sending/transmitting a two-step Msg1 1920. The parametermay indicate at least one of the following: a PRACH resource allocation,a preamble format, SSB information (e.g., a total number/quantity ofSSBs, downlink resource allocation of SSB transmission, a transmissionpower of SSB transmission, and/or other information), and/or uplinkradio resources for one or more transport block transmissions.

A wireless device may send/transmit, via a cell and to a base station,an RAP for UL time alignment and/or one or more transport blocks (e.g.,delay-sensitive data, wireless device ID, security information, deviceinformation, such as IMSI, and/or other information) in a ULtransmission of a two-step RA procedure. A base station maysend/transmit a two-step Msg2 1950 (e.g., an RAR), for example, in a DLtransmission of the two-step RA procedure. The two-step Msg2 1950 maycomprise at least one of the following: a timing advance commandindicating the TA value, a power control command, a UL grant (e.g.,radio resource assignment, and/or MCS), a wireless device ID forcontention resolution, an RNTI (e.g., C-RNTI or TC-RNTI), and/or otherinformation. The two-step Msg2 1950 (e.g., an RAR) may comprise apreamble indicator/identifier corresponding to the preamble 1930, apositive or negative acknowledgement of a reception of the one or moretransport blocks 1940, and/or an indication of a successful decoding ofthe one or more transport blocks 1940. A two-step RA procedure mayreduce RA latency in comparison with a four-step RA procedure, forexample, by integrating a random access preamble transmission (e.g., aprocess to obtain a timing advance value) with one or more transportblock transmissions.

A wireless device may send/transmit, via a cell and to a base station,an RAP in parallel with one or more TBs at least during a portion oftime, for example, in a UL transmission of a two-step RA procedure. Thewireless device may acquire one or more configuration parameters for theUL transmission, for example, before the wireless device starts atwo-step RA procedure (e.g., at step 1910 in FIG. 19). The one or moreconfiguration parameters may indicate at least one of the following: aPRACH resource allocation, a preamble format, SSB information (e.g., anumber/quantity of transmitting SSBs, downlink resource allocation ofSSB transmissions, a transmission power of SSB transmission, and/orother information), uplink radio resources (in terms of time, frequency,code/sequence/signature) for one or more transport block transmissions,and/or power control parameters of one or more TB transmissions (e.g.,cell and/or UE specific power adjustments used for calculating receivedtarget power, inter-cell interference control parameter that may be usedas a scaling factor of pathloss measurement, reference signal power tocalculate for pathloss measurement, and/or one or more margins).

A wireless device may generate a RAP. A two-step RACH configuration maycomprise an RAP generating parameters (e.g., a root sequence) that maybe used by the wireless device to generate an RAP. The wireless devicemay use the RAP generating parameters to generate one or more candidatepreambles and/or the wireless device may randomly select one of thecandidate preambles as the RAP. The RAP generating parameters may be SSBspecific and/or cell-specific. RAP generating parameters for a first SSBmay be different from, or the same as, an RAP generating parameters fora second SSB. A base station may send/transmit a control message (e.g.,an RRC message for a handover, and/or a PDCCH order for a secondary celladdition) that comprises a preamble index of an RAP dedicated to awireless device, for example, to initiate a two-step RA procedure. Theone or more candidate preambles may be classified or organized intogroups that may indicate an amount of data for transmission. The amountof data may indicate one or more transport blocks that remain in thebuffer. Each of the groups may be associated with a range of a datasize. A first group of the groups may comprise RAPs associated with(e.g., indicated for) small data transmissions. A second group maycomprise RAPs associated with (e.g., indicated for) large/larger datatransmissions. A base station may send/transmit an RRC messagecomprising one or more thresholds with which a wireless device maydetermine a group of RAPs (e.g., by comparing the one or more thresholdsand the amount of data). The wireless device may be able to indicate asize of data for transmission, for example, by sending/transmitting anRAP determined/selected from a specific group of RAPs.

A wireless device may send/transmit the RAP via a RACH resourceindicated by a two-step RACH configuration, for example, in a two-stepRA procedure. The wireless device may send/transmit one or more TBs viaa UL radio resource indicated by a two-step RACH configuration. Thetransmission of the RAP may be overlapped in time (e.g., partially orentirely) with the transmission of the one or more TBs. The two-stepRACH configuration may indicate an overlapped portion of radio resourcesbetween the RAP and one or more TB transmissions. The two-step RACHconfiguration may indicate one or more UL radio resources associatedwith one or more RAPs (or RAP groups) and/or the RACH resource. Awireless device may determine at least one UL radio resource via whichthe wireless device may send/transmit one or more TBs as a part of atwo-step RACH procedure, for example, based on a determination/selectionof an RAP, an RAP group, and/or a RACH resource. The one or more ULradio resources may be indicated based on a frame structure (e.g., shownin FIG. 6), and/or an OFDM radio structure (e.g., shown in FIG. 8), forexample, with respect to an SFN (SNR=0), a slot number, and/or an OFDMsymbol number for a time domain radio resource, and/or with respect to asubcarrier number, a number of resource elements, a number of resourceblocks, an RBG number, and/or a frequency index for a frequency domainradio resource. The one or more UL radio resources may be indicatedbased on a time offset and/or a frequency offset with respect to one ormore RACH resources of a selected RAP. The UL transmissions may occur,for example, in the same subframe (or slot/mini-slot), in consecutivesubframes (or slot/mini-slot), or in the same burst.

A listen-before-talk (LBT) procedure may be implemented for transmissionin an unlicensed cell (or an unlicensed band, an unlicensed sub-band,etc.). A cell operating in an unlicensed band may be referred to as anunlicensed cell, an LAA cell, and/or an NR-U cell. The unlicensed cellmay be operated as non-standalone with an anchor cell in a licensed bandor standalone without an anchor cell in a licensed band. An LBTprocedure may comprise a clear channel assessment (CCA). In an LBTprocedure, a wireless device (e.g., equipment) may apply a CCA beforeusing the unlicensed cell or channel. The CCA may comprise an energydetection that may determine the presence of other signals on a channel(e.g., channel is occupied) or absence of other signals on a channel(e.g., channel is clear/unoccupied). A regulation of a country mayimpact the LBT procedure. For example, European and Japanese (or othercountry/region/area) regulations may mandate the usage of an LBTprocedure in the unlicensed bands, such as the 5 GHz unlicensed band.Apart from regulatory requirements, carrier sensing via an LBT proceduremay be used to allow different devices and/or networks attempting toutilize the unlicensed band to share the resources of the unlicensedband.

A channel reservation may be enabled by a transmission of signals, by acell (e.g., an NR-U cell), after or in response to gaining channelaccess based on a successful LBT operation/procedure. Other nodes (e.g.,one or more device (e.g., Wi-Fi node(s), LAA cell, and/or NR-U cell)operating in an unlicensed band) may receive the signals (e.g.,sent/transmitted for the channel reservation) with an energy level abovea certain threshold. The other nodes may determine that the channel isoccupied. Functions that may need to be supported by one or more signalsfor operation in an unlicensed band with discontinuous downlinktransmission may comprise one or more of the following: detection of thedownlink transmission in an unlicensed band (e.g., including cellidentification) by wireless devices; and/or time and/or frequencysynchronization of wireless devices.

Downlink transmission and frame structure design for operation in anunlicensed band may use subframe, (mini-)slot, and/or symbol boundaryalignment according to timing relationships across serving cellsaggregated by a carrier aggregation. This use may not imply that basestation transmissions start at the subframe, (mini-)slot, and/or symbolboundary. Unlicensed cell operation (e.g., LAA and/or NR-U) may supporttransmitting PDSCH transmissions, for example, if not all OFDM symbolsare available for transmission in a subframe according to an LBTprocedure. Delivery of control information for the PDSCH transmission(s)may be supported.

An LBT procedure (and/or a channel access procedure) may be used forcoexistence of a radio access technology (e.g., LTE, NR, or any otheraccess technology) with other operators and technologies operating in anunlicensed band. A node attempting to send/transmit a signal via acarrier in an unlicensed band may perform a CCA as a part of an LBTprocedure to determine if the channel is free for use. The LBT proceduremay involve energy detection to determine if the channel is being used.Regulatory requirements in some regions/countries/areas (e.g., inEurope) may specify an energy detection threshold such that if a nodereceives energy greater than the threshold, the node mayassume/determine that the channel is being used and/or is not available.While nodes may follow such regulatory requirements, a node mayoptionally use a lower threshold for energy detection than that may bespecified by regulatory requirements. A radio access technology (e.g.,LTE, NR, and/or any other access technology) may use a mechanism toadaptively change the energy detection threshold. The radio accesstechnology (e.g., NR-U) may use a mechanism to adaptively lower theenergy detection threshold from an upper bound. An adaptation mechanismmay not preclude static or semi-static setting of the threshold. Acategory 4 LBT (CAT4 LBT) mechanism and/or other type of LBT mechanismmay be implemented.

Various example LBT mechanisms may be implemented. At least oneconfiguration may be such that no LBT procedure may be performed by asending/transmitting entity (e.g., a wireless device and/or a basestation), for example, for some signals, in some implementationscenarios, in some situations, and/or in some frequencies. A category 1(CAT1, e.g., no LBT) may be implemented in one or more cases. If achannel in an unlicensed band may be occupied by a first device (e.g., abase station for DL transmission), a second device (e.g., a wirelessdevice) may take over the channel for a transmission without performingthe CAT1 LBT. A category 2 (CAT2, e.g. LBT without random back-offand/or one-shot LBT) may be implemented. The duration of timedetermining that the channel is idle may be deterministic (e.g., by aregulation). A base station may send/transmit an uplink grant indicatinga type of LBT procedure (e.g., CAT2 LBT) to a wireless device. CAT1 LBTand CAT2 LBT may be used for COT sharing. A base station maysend/transmit an uplink grant comprising a type of LBT procedure. Awireless device may send/transmit uplink control information comprisinga type of LBT procedure. CAT1 LBT and/or CAT2 LBT in the uplink grant(or uplink control information) may indicate, to a receiving device(e.g., a base station and/or a wireless device) to trigger COT sharing.Category 3 (CAT3, e.g., LBT with a random back-off with a contentionwindow of a fixed size) may be implemented. The LBT procedure may havethe following procedure as one of its components. Thesending/transmitting entity (e.g., a wireless device and/or a basestation) may draw a random quantity/number N within a contention window.The size of the contention window may be specified by the minimum andmaximum value of N. The size of the contention window may be fixed. Therandom quantity/number N may be used in the LBT procedure to determinethe duration of time that the channel is determined (e.g., sensed) to beidle before the sending/transmitting entity sends/transmits a signal viathe channel Category 4 (CAT4, e.g., LBT with a random back-off with acontention window of a variable size) may be implemented. Thesending/transmitting entity (e.g., a wireless device and/or a basestation) may draw/determine a random quantity/number N within acontention window. The size of contention window may be specified by theminimum and maximum value of N. The sending/transmitting entity may varythe size of the contention window, for example, if drawing/determiningthe random quantity/number N. The random quantity/number N may be usedin the LBT procedure to determine the duration of time that the channelmay be determined (e.g., sensed) to be idle before thesending/transmitting entity sends/transmits a signal via the channel.

A wireless device may use an UL LBT. The UL LBT may be different from aDL LBT (e.g., by using different LBT mechanisms or parameters), forexample, a radio access technology UL (e.g., NR-U UL) may be based onscheduled access which may affect channel contention opportunities of awireless device. Other considerations motivating a different UL LBT maycomprise, but are not limited to, multiplexing of multiple wirelessdevices in a subframe (slot, and/or mini-slot).

DL transmission burst(s) may be a continuous (unicast, multicast,broadcast, and/or combination thereof) transmission by a base station(e.g., to one or more wireless devices) via (e.g., on) a carriercomponent (CC). UL transmission burst(s) may be a continuoustransmission from one or more wireless devices to a base station via(e.g., on) a CC. DL transmission burst(s) and UL transmission burst(s)on a CC in an unlicensed band may be scheduled in a TDM manner over thesame unlicensed carrier. Switching between DL transmission burst(s) andUL transmission burst(s) may require an LBT procedure (e.g., CAT1 LBT,CAT2 LBT, CAT3 LBT, and/or CAT4 LBT). An instant in time may be part ofa DL transmission burst or a UL transmission burst.

A failure of a random access may occur due to an LBT procedure, forexample, in an unlicensed band. At least one LBT procedure may beperformed, for example, prior to DL and/or UL transmission in anunlicensed band. In a random access procedure (e.g., in FIG. 12), Msg 11220, Msg 2 1230, Msg 3 1240, and contention resolution 1250 may requireat least one LBT procedure before the transmission for contention-basedrandom access (e.g., at least 4 LBTs). For contention-free randomaccess, Msg 1 1220 and Msg2 1230 may require at least one LBT (e.g., atleast 2 LBTs).

FIG. 20 shows contention based and contention-free random accessprocedures with LBT. A successful contention based random accessprocedure may use Msg 1 2020, Msg 2 2030, Msg 3 2040, and contentionresolution 2050 to perform the RA procedure with the wireless device 110and base station 120. The wireless device may perform a first LBT,determine that the medium is clear, and send Msg 1 2020 to a basestation 120. The base station 120 may perform a second LBT, determinethat the medium is clear, and send Msg 2 2030 to the wireless device110. The wireless device 110 may perform a third LBT, determine themedium is clear, and send Msg 1 2040 to the base station 120. The basestation 1120 may perform a fourth LBT, determine that the medium isclear, and sends contention resolution 2050 to the wireless device 110.

A successful contention-free based RA procedure may use Msg 1 2020 andMsg 2 2030 to perform the RA procedure with the wireless device 110 andthe base station 120. The wireless device 110 may perform a first LBT,determine that the medium is clear, and send Msg 1 2020 to the basestation 120. The base station 120 may perform a second LBT, determinethat the medium is clear, and send Msg 2 2030 to the wireless device110.

A failure of a RA may occur due to LBT, for example, in an unlicensedband. At least one LBT may be performed prior to DL and/or ULtransmission. Msg 1 1220, Msg 2 1230, Msg 3 1240, and/or contentionresolution 1250 may require at least one LBT before the transmission(e.g., at least 4 LBTs), for example, in a contention based randomaccess procedure. Msg 1 1220 and Msg2 1230 may require at least one LBTeach (e.g., at least 2 LBTs), for example, for a contention-free randomaccess procedure. A base station and/or a wireless device may not send(e.g., transmit) a message (e.g., Msg 1 2020, Msg 2 2030, Msg 3 2040,and/or contention resolution 2050) for a RA procedure, for example, ifthe LBT procedure has failed prior to sending the message (e.g., CCA inLBT determines that a channel in an unlicensed band is busy (e.g.,occupied by another device)).

A failure of an LBT procedure may result in degrading a user experience(e.g., in terms of QoS, capacity (e.g., throughput), and/or coverage). Abase station and/or a wireless device may wait until the channel becomesidle. This waiting may result in a latency problem to make a radio linkconnection between a base station and a wireless device. A failure of anLBT during a RA procedure may lead a long delay for a wireless device toreceive an UL grant and/or TA value from a base station. This delay mayresult in a call drop and/or traffic congestion. A failure of an LBTprocedure in a RA procedure for an SCell addition may lead a cellcongestion (e.g., load imbalancing) on one or more existing cells (e.g.,if an SCell may not take over traffic from the one or more existingcells in time).

An efficiency of RA procedure operating in an unlicensed band maydegrade with LBT failure, which may cause a latency/delay, and/orperformance degradation. A wireless device and/or a base station mayhave one or more transmission opportunities in a time and/or frequencydomain during an RA procedure. Selecting one or more SSBs and performingone or more LBT procedures via one or more PRACH occasions associatedwith the one or more SSBs may increase a success rate of LBT procedures.A wireless device may measure a plurality of downlink reference signals(e.g., SSBs or CSI-RSs, if CSI-RS is configured by RRC). The wirelessdevice may select two or more SSBs by comparing RSRPs of the pluralityof downlink reference signals and a threshold. The threshold maycomprise a RSRP threshold SSB parameter (e.g., rsrp-ThresholdSSB) if theplurality of downlink reference signals are SSBs. The threshold maycomprise a RSRP threshold CSI-RS parameter (e.g., rsrp-ThresholdCSI-RS)if the plurality of downlink reference signals are CSI-RSs. The wirelessdevice may select two or more downlink referencing signals (SSBs orCSI-RSs) having RSRPs that are higher than the threshold. The wirelessdevice may determine one or more PRACH occasions associated with theselected two or more downlink reference signals (e.g., SSBs), forexample, based on SSBs being configured with the wireless device. Thewireless device may determine the one or more PRACH transmissions basedon an association between PRACH occasions and SSBs that may be indicatedby one or more RRC parameters (e.g., ra-ssb-OccasionMaskIndex). Thewireless device may determine one or more PRACH occasions associatedwith the selected two or more downlink reference signals (e.g.,CSI-RSs), for example, based on CSI-RSs being configured with thewireless device. The wireless device may determine the one or more PRACHtransmissions based on an association between PRACH occasions andCSI-RSs that may be indicated by one or more RRC parameters (e.g.,ra-OccasionList).

FIG. 21 shows an example diagram of a two-step RA procedure with LBT. Atwo-step RA procedure may employ LBT in an unlicensed band. A basestation and/or a wireless device may not send (e.g., transmit) a message(e.g., two-step Msg 1 2120 (e.g., Msg A), preamble 2130, one or more TBs2140, and/or two-step Msg 2 2150 (e.g., Msg B)) for a RA procedure ifLBT is failed prior to sending (e.g., transmitting) the message (e.g.,CCA in LBT determines that a channel in an unlicensed band is busy,e.g., occupied by other device). The transmissions of the preamble 2130and for one or more TBs 2140 may have a same LBT procedure and/ordifferent LBT procedures.

Radio resources for transmissions of a preamble 2130 and/or one or moreTBs 2140 may be configured in a same channel (or a same subband or asame BWP or a same UL carrier), where a wireless device performs an LBTprocedure for the transmissions (e.g., based on a regulation). An LBTresult on the same channel (or the same subband or the same BWP or thesame UL carrier) may be applied for transmissions of the preamble 2130and for one or more TBs 2140.

FIG. 22 shows an example of radio resource allocation for a two-step RAprocedure. PRACH resource 2230 and UL radio resources 2240 may betime-multiplexed, for example, based on a frequency offset in FIG. 22being zero. PRACH 2230 resource and UL radio resources 2240 may befrequency-multiplexed, for example, based on a timeoffset in FIG. 22being zero. The frequency offset in FIG. 22 may be an absolute number interms of Hz, MHz, and/or GHz, and/or a relative number (e.g., one ofindex from a set of frequency indices that arepredefined/preconfigured). The timeoffset in FIG. 22 may be an absolutenumber in terms of micro-second, milli-second, and/or second and/or arelative number (e.g., in terms of subframe, slot, mini-slot, OFDMsymbol). PRACH resource 2230 for transmission of the preamble 2130 andUL radio resources for transmission of one or more TBs 2140 may besubject to one LBT procedure if f1 2210 and f2 2220 are configured inthe same channel (or a same subband or a same BWP or a same UL carrier).One LBT procedure before a PRACH resource 2230 may be performed by awireless device (e.g., based on a regulation of unlicensed band). Aquantity of LBT procedures may be determined based on a value of thetimeoffset. One LBT procedure before a PRACH resource 2230 may beperformed by a wireless device, for example, if the value of a timeoffset is equal to and/or less than a threshold (e.g., that may beconfigured and/or defined by a regulation). The one LBT procedure maydetermine idle and a wireless device may perform a transmission of thepreamble 2130 via PRACH resource 2230 followed by a second transmissionof one or more TBs 2140 via the UL radio resources 2240 with no LBTprocedure (the transmission order may be switched if the UL radioresources 2240 is allocated before PRACH resource 2230 in time domain).PRACH and UL radio resources may be allocated closely enough in timedomain. A wireless device may perform a first LBT procedure before aPRACH resource 2230 and perform a second LBT procedure before UI radioresources 2240, for example, based on the value of timeoffset beinglarger than the threshold.

A wireless device may perform an LBT procedure and apply a result (e.g.,idle or busy) of the LBT procedure to the transmission of the preamble2130 and UL radio resources for transmission of one or more TBs 2140. Abandwidth of BWP and/or UL carrier (e.g., where f1 2210 and f2 2220 areconfigured), may be larger than a particular value (e.g., 20 MHz). Thebandwidth may be less than the particular value (e.g., 20 MHz). Awireless device may perform the transmissions of the preamble 2130 andfor one or more TBs 2140, for example, if the channel is idle. Atransmission of the preamble 2130 may be followed by a transmission ofone or more TBs 2140 (or vice versa).

A wireless device may perform a first transmission of the preamble 2130that may be partially overlapped in time with a second transmission ofone or more TBs 2140. A wireless device may not perform thetransmissions of the preamble 2130 and for one or more TB s 2140, forexample, based on the channel being busy. A wireless device may performa particular LBT procedure (e.g., CAT2 LBT) for the first transmission,for example, after or in response to the first transmission (and/orafter or in response to an LBT procedure performed for the firsttransmission).

Radio resources for transmissions of the preamble 2130 and one or moreTBs 2140 may be configured in different channels, different subbands,different BWPs, and/or different UL carriers (e.g., one in NUL and theother one in SUL) that may require separate LBT procedures. A wirelessdevice may perform a LBT procedure per one or more channels, per one ormore subbands, per one or more BWPs, and/or per one or more UL carriers.

FIG. 23 shows an example of one or more LBT procedures performed for atwo-step RA procedure UL radio resources 2350 may be allocated before oraligned with PRACH resources 2330 in time. A wireless device may performa first LBT procedure (e.g., LBT 2340 in FIG. 23) before a firsttransmission of preamble 2130 (e.g., via PRACH resources 2330) andperform a second LBT procedure (e.g., LBT 2360 in FIG. 23) before asecond transmission of one or more TBs 2140 (e.g., via UL radioresources 2350). A wireless device may perform none of, one of, or bothof the first transmission and the second transmission, depending onresults of the first LBT procedure and second LBT procedure. SeparateLBTs before a PRACH message and/or data may provide benefits, such as:earlier transmission of the first transmission and/or secondtransmission by a wireless device, earlier transmission of a preamblethan if a larger LBT were used, and increased probability that atransmission will be successful.

The first transmission may be performed if a first result of the firstLBT procedure is idle. The second transmission may be independent of thefirst result. The second transmission may be performed if a secondresult of the second LBT procedure is idle. A wireless device may send(e.g., transmit) the preamble 3330, for example, in response to thefirst LBT procedure being idle. The wireless device may not be able tosend (e.g., transmit) one or more TBs 3340 in response to the second LBTprocedure being busy. A wireless device may not send (e.g., transmit)the preamble 3330 in response to the first LBT procedure being busy. Thewireless device may send (e.g., transmit) one or more TBs 3340 inresponse to the second LBT procedure being idle. In a two-step RAprocedure, one or more TBs may comprise an identifier of the wirelessdevice, for example, so that a base station may identify and/or indicatewhich wireless device sent (e.g., transmitted) the one or more TBs. Theidentity may be configured by the base station and/or may be at least aportion of wireless device-specific information (e.g., resume ID, DMRSsequence/index, IMSI, etc.). A base station may identify and/or indicatethe wireless device based on the identity in the one or more TBs, forexample, based on a wireless device sending (e.g., transmitting) one ormore TBs with no preamble 3330 (e.g., if a channel, e.g. PRACH 2330 isbusy).

Separate LBT procedures for transmissions of a preamble and one or moreTBs may be performed, for example, based on a two-step RA procedureconfigured in an unlicensed band. A wireless device may be configured(e.g., by a base station) with separate LBT procedures for a widebandoperation (e.g., based on a bandwidth greater than 20 MHz). A wirelessdevice may be configured (e.g., by a base station) with a widebandcomprising one or more subbands and/or one or more BWPs, for example,based on wideband operation. Some of the one or more subbands mayoverlap in the frequency domain. Some of the one or more subbands maynot overlap in the frequency domain. Some of the one or more BWPsoverlap in the frequency domain. Some of the one or more BWPs may notoverlap in the frequency domain. Separate LBT procedures may be used fortransmissions via the two radio resources, for example, based on awideband operation and/or two radio resources being allocated with aspace larger than a threshold (e.g., 20 MHz). A wideband may compriseone or more subbands, and two radio resources may be allocated indifferent subbands. A first transmission scheduled in a first subbandmay use a first LBT procedure, and a second transmission scheduled in asecond subband may use a second LBT procedure. The first LBT procedureand the second LBT procedure may be independent of each other.

UL radio resources for transmission of one or more TBs 2140 may besubject to a first LBT procedure (e.g., LBT 2360) and be independent ofa second LBT procedure (e.g., LBT 2340) for transmission of the preamble2130. PRACH resources 2330 for transmission of the preamble 2130 may besubject to a second LBT procedure (e.g., LBT 2360) and be independent ofa first LBT procedure (e.g., LBT 2360) for transmission of one or moreTBs 2140. A wireless device may perform separate LBT procedures for afirst transmissions of the preamble 2130 and a second transmission ofone or more TBs 2140, for example, based on f1 2310 and f2 2320 beingconfigured in different channels, different subbands, different BWPs,and/or different UL carriers.

FIG. 24A and FIG. 24B are examples of one or more LBT proceduresperformed for a two-step RA procedure in an unlicensed band. Theresource allocation and the separate LBT procedures in FIG. 23 may beresulted from FIG. 24A and/or FIG. 24B. A wireless device may beconfigured (e.g., by a base station) with one or more PRACH resourcesand one or more UL radio resources in different channels (BWPs and/or ULcarriers). The wireless device may one or more first opportunities tosend (e.g., transmit) preambles and one or more second opportunities tosend (e.g., transmit) one or more TBs. A wireless device may have twoopportunities via random access resources (e.g., PRACH resource 2430 andPRACH resource 2330) for preamble transmission, for example, as shown inFIG. 24A. A wireless device may select one of two opportunities, forexample, based on LBT results. A wireless device may perform a first LBTprocedure (e.g., LBT 2440) and a second LBT procedure (e.g., LBT 2340 asshown in FIG. 24A). A wireless device may select one of PRACH resourcesassociated either a first LBT procedure or a second LBT procedure (e.g.,based on random selection), for example, based on the results of thefirst and second LBT procedures being idle. A wireless device may selecta PRACH resource associated with the LBT result being idle for preambletransmission, for example, based on one of LBT result being idle and theother of LBT result being busy. A wireless device may not send (e.g.,transmit) a preamble and may perform one or more LBT procedures for oneor more TB transmissions, for example, based on the first and second LBTprocedure results being busy.

A wireless device may have one or more opportunities for transmission ofone or more TBs via UL radio resources (e.g., in a similar way that awireless device has for preamble transmission above). The one or moreopportunities for transmission of one or more TBs may be independent ofone or more opportunities for transmission of preamble. The wirelessdevice may perform one or more LBT procedures to gain access to achannel to send (e.g., transmit) one or more TBs, for example, based ona wireless device not sending (e.g., transmitting) a preamble due to aresult (e.g., busy) of LBT procedure. A wireless device may perform afirst LBT procedure (e.g., LBT 2420) followed by a first transmissionopportunity of one or more TBs via first UL radio resources 2410 and asecond LBT procedure (e.g., LBT 2360 in FIG. 24A) followed by a secondtransmission opportunity of one or more TBs via second UL radioresources 2350, as shown in FIG. 24A. A wireless device may select oneof the opportunities, for example, depending on LBT results. A wirelessdevice may send (e.g., transmit) one or more TBs via UL radio resources2350, for example, based on LBT 2420 being busy and/or LTB 2360 beingidle as shown in FIG. 24A. A wireless device may not send (e.g.,transmit) any preamble, for example, based on one or more LBT procedures(e.g., LBT 2340 and LBT 2440 in FIG. 24A) to gain access for sending(e.g., transmitting) a preamble result in busy. A wireless device mayperform one or more second LBT procedures (e.g., LBT 2420 and LBT 2360in FIG. 24A) for transmission of one or more TBs.

The wireless device may receive, from a base station, one or morecontrol message (e.g., RRC messages and/or PDCCH messages) indicatingone or more associations between PRACH resources and UL radio resources,for example, before a wireless device initiates a two-step RA procedure.The associations may be one-to-one, multi-to-one, one-to-multi, and/ormulti-to-multi between one or more PRACHs resources and one or more ULradio resources. A wireless device may determine which UL radioresources and/or which PRACH resources to select, for example, based onthe associations. The associations may indicate one-to-multi associationfrom PRACH resource 2330 to UL radio resources 2350 and UL radioresources 2410, for example, as shown in FIG. 24A. The associations mayindicate one-to-one association from PRACH resources 2430 to UL radioresources 2350. A wireless device may perform one or more LBT procedures(depending on a regulation and/or resource allocation whether theresources are in the same channel) for transmission of one or more TBsdepending on a selection of PRACH resources. A wireless device mayperform two LBT procedures (LBT 2340 and LBT 2440), for example, asshown in FIG. 24A. A wireless device may send (e.g., transmit) apreamble via PRACH resources 2330, for example, based on LBT 2340 beingidle but LBT 2440 being busy. The wireless device may determine (e.g.,select) one or more candidate UL radio resources based on a configuredassociation of PRACH resources 2330, which may be one-to-multi fromPRACH resources 2330 to UL radio resources 2350 and UL radio resources2410. The wireless device may perform LBT 2420 and LBT 2360 based on theconfigured association. A wireless device may send (e.g., transmit) oneor more TBs, depending on the results of the LBT procedures. FIG. 24B isan example of a two-step RA procedure. UL radio resources are associatedwith one PRACH resource. An association may be configured (e.g., by abase station) from PRACH resource 2330 to UL radio resource 2350 and ULradio resources 2450.

The PRACH resource and/or UL radio resources in FIG. 22, FIG. 23, FIG.24A, and/or FIG. 24B may be associated with at least one referencesignal configuration (e.g., SSB, CSI-RS, DM-RS). A wireless device mayreceive (e.g., from a base station) at least one control message toindicate such an association. A configuration of each reference signalmay have an association with at least one PRACH resource, that may beconfigured by RRC message and/or PDCCH signals, for example, based onthe base station sending (e.g., transmitting) a plurality of referencesignals. In one or more downlink channels, there may be a plurality ofPRACH resources and a plurality of UL radio resources associated withthe plurality of PRACH resources.

A failure of a LBT procedure may result in degrading a user experience(e.g., in terms of QoS, capacity (throughput), and/or coverage). A basestation and/or a wireless device may wait until the channel becomesidle. This wait may result in a latency problem to make a radio linkconnection between a base station and a wireless device. A failure of anLBT procedure during a RA procedure may lead a long delay for a wirelessdevice to receive an UL grant and/or TA value from a base station. Thisfailure may result in a call drop and/or traffic congestion. A failureof an LBT in a RA procedure for an SCell addition may lead to cellcongestion (e.g., load imbalancing) on one or more existing cells, forexample, because an SCell may not take over traffic from the one or moreexisting cells in time.

FIG. 25 shows an example of an association between downlink referencesignals and random access resource (e.g., PRACH) occasions. A basestation 120 may send a plurality (e.g., a burst, such as up to Kquantity) of DL reference signals 2502A-2502K. A wireless device 110 mayselect one or more random access resources (e.g., PRACH occasions2504A-2504K that may each correspond to at least one of a K quantity ofDL reference signals 2502A-2502K) to attempt a RA procedure (e.g., senda RAP). The wireless device 110 may perform the RA procedure on a firstavailable (e.g., clear) random access resource.

An association between a DL reference signal and random access resources(e.g., PRACH occasions) may be one-to-one mapping and/or multi-to-onemapping between DL reference signals and random access resourceoccasions (e.g., PRACH occasions). A wireless device 110 may measure kDL reference signals. A wireless device 110 may select DL referencesignal 1 2502A, DL reference signal 2 2502B, and DL reference signal 32502C. The wireless device 110 may perform up to a particular quantityof LBT procedures (e.g., at most 3 LBTs). Each LBT procedure may beperformed prior to each of the selected random access resource occasions(e.g., PRACH occasions), for example, if random access resource occasion(e.g., PRACH occasion) 1 2504A, random access resource occasion (e.g.,PRACH occasion) 2 2504B, and random access resource occasion (e.g.,PRACH occasion) 3 2504C are associated with DL reference signal 1 2502A,DL reference signal 2 2502B, and DL reference signal 3 2502C,respectively.

A type of LBT may be pre-defined and/or semi-statically by a basestation. A base station may indicate a type of LBT of random accessresource occasions (e.g., PRACH occasions) in a RACH configuration. Thetype may be one of CAT 1, CAT 2, CAT 3, CAT 4 (or long LBT and/or shortLBT).

A wireless device may send (e.g., transmit) one or more preambles viathe first random access resource occasion (e.g., PRACH occasion). Thewireless device may not perform one or more LBT procedures in otherrandom access resource occasions (e.g., PRACH occasions) that may beavailable after the first random access resource occasions (e.g., PRACHoccasions) in the same PRACH burst, for example, if an LBT successoccurs (e.g., channel is idle) in a first random access resourceoccasion (e.g., PRACH occasion). The wireless device may not performanother LBT procedure on random access resource occasion (e.g., PRACHoccasion) 3 2504C, for example, if the wireless device selects randomaccess resource occasion (e.g., PRACH occasion) 1 2504A and a randomaccess resource occasion (e.g., PRACH occasion) 3 2504C, and an LBTprocedure on random access resource occasion (e.g., PRACH occasion) 12504A is successful. The wireless device may perform one or more LBTprocedures prior to each of random access resource occasions (e.g.,PRACH occasions) in a first frequency (e.g., Freq. 1) at least until anLBT procedure is successful, for example, if a wireless device selectsall random access resource occasions (e.g., PRACH occasions) in thefirst frequency (e.g., Freq. 1 in FIG. 25). The wireless device may send(e.g., transmit) one or more preambles associated with a random accessresource occasion (e.g., PRACH occasion) if the LBT procedure issuccessful, for example, based on or in response to the LBT procedurebeing successful.

A wireless device may perform an LBT procedure for the one or morerandom access resource occasions (e.g., PRACH occasions) FDM-ed, whichmay be firstly available and/or may be randomly selected, for example,if one or more random access resource occasions (e.g., PRACH occasions)are frequency domain multiplexed (FDM-ed), e.g., random access resourceoccasion (e.g., PRACH occasion) 1 2504A and random access resourceoccasion (e.g., PRACH occasion) 2 2504B. A wireless device may (e.g.,based on RSRPs of DL reference signals) select random access resourceoccasion (e.g., PRACH occasion) 1 2504A and random access resourceoccasion (e.g., PRACH occasion) 2 2504B FDM-ed. The wireless device mayperform LBT procedure(s) on random access resource occasion (e.g., PRACHoccasion) 1 2504A and random access resource occasion (e.g., PRACHoccasion) 2 2504B. The wireless device may randomly select one of theserandom access resource occasions, for example, if both LBT proceduresare successful. The wireless device may select an available randomaccess resource occasion first in time domain, for example, if both LBTprocedures are successful. The wireless device may select a randomaccess resource occasion corresponding to a DL reference signal havingan RSRP that is greater than other DL reference signals, for example, ifboth LBT procedures are successful. Random access resource occasion(e.g., PRACH occasion) 1 2504A and random access resource occasion(e.g., PRACH occasion) 2 2504B may be FDM-ed within a threshold (e.g.,less than a bandwidth threshold). The wireless device may perform awideband LBT procedure that may cover a frequency range of random accessresource occasion (e.g., PRACH occasion) 1 2504A and random accessresource occasion (e.g., PRACH occasion) 2 2504B. The wireless devicemay select one of the random access resource occasions (e.g., PRACHoccasions) based on: a random selection, time location of random accessresource occasions (e.g., PRACH occasions), and/or RSRPs ofcorresponding DL reference signals, for example, if the wideband LBTprocedure is successful.

A wireless device may perform a long LBT on a first random accessresource occasion (e.g., PRACH occasion) firstly available. The wirelessdevice may perform a short LBT on a second random access resourceoccasion (e.g., PRACH occasion) following (e.g., after) the first randomaccess resource occasion (e.g., PRACH occasion), for example, if the LBTon the first random access resource occasion (e.g., PRACH occasion)fails (e.g., a long LBT procedure for random access resource occasion(e.g., PRACH occasion) 1 2504A fails and/or a short LBT procedure forrandom access resource occasion (e.g., PRACH occasion) 3 2504C fails). Atype of LBT procedure on the second random access resource occasion(e.g., PRACH occasion) may be configured by a base station. A type ofLBT procedure on the second random access resource occasion (e.g., PRACHoccasion) may be determined by a time difference of two random accessresource occasions (e.g., PRACH occasions). The first random accessresource occasion (e.g., PRACH occasion) and the second random accessresource occasion (e.g., PRACH occasion) may have a guard time less thana threshold (e.g., configurable or pre-defined, such as 25 us, 16 us, orany other duration). The wireless device may perform a short LBTprocedure on the second random access resource occasion (e.g., PRACHoccasion), for example, if the first random access resource occasion andthe second random access resource occasion have a guard time less than athreshold. The wireless device may perform a long LBT procedure, forexample, if the first random access resource occasion and the secondrandom access resource occasion have a guard time greater than or equalto the threshold.

The wireless device 110 may perform an LBT procedure before eachselected random access resource occasion, for example, at least untilsuccessful or until an LBT procedure before each of the selected randomaccess resource occasions have failed. The wireless device 110 mayperform a RA procedure on a random access resource occasion associatedwith a successful LBT procedure. The two or more random access resourceoccasions (e.g., PRACH occasions) 2504A-2504F may not be aligned.

A wireless device may select two or more random access resourceoccasions (e.g., PRACH occasions), for example, based on RSRPs of DLreference signals. A wireless device may select random access resourceoccasion (e.g., PRACH occasion) 1 2504A, random access resource occasion(e.g., PRACH occasion) 2 2504B, and/or random access resource occasion(e.g., PRACH occasion) 3 2504C. The wireless device may perform a firstLBT procedure on a first random access resource occasion (e.g., PRACHoccasion) available firstly in time (e.g., random access resourceoccasion (e.g., PRACH occasion) 1 2504A). The wireless device maydetermine a second LBT procedure on a second random access resourceoccasion (e.g., PRACH occasion), for example, based on the first LBTprocedure. The wireless device may send (e.g., transmit) a preamble viathe first random access resource occasion (e.g., PRACH occasion), forexample, if the first LBT procedure was successful. The wireless devicemay determine to perform a second LBT procedure on a second randomaccess resource occasion (e.g., PRACH occasion) available firstly afterthe first random access resource occasion (e.g., PRACH occasion) (e.g.,random access resource occasion (e.g., PRACH occasion) 2 2504B), forexample, if the first LBT procedure was not successful. The wirelessdevice may perform a third LBT procedure on a third random accessresource occasion (e.g., PRACH occasion), for example, if the second LBTprocedure on the second random access resource occasion (e.g., PRACHoccasion) has failed. The wireless device may perform a wideband LBT,for example, if one or more FDM-ed random access resource occasions(e.g., PRACH occasions) are configured within a guard time less than athreshold. The wireless device may perform LBT procedures on the one ormore FDM-ed random access resource occasions (e.g., PRACH occasions). Awireless device may send (e.g., transmit) a plurality of preambles via aplurality of random access resource occasions (e.g., PRACH occasions).

FIG. 26 shows an example one or more random access resource occasionconfigurations (e.g., PRACH occasions). The random access resourceoccasions may be separated by time and/or frequencies (e.g., TDM-edand/or FDM-ed). The random access resource occasions may be separated bygaps (e.g., PRACH occasions 2604A-2604D via freq. 1). The random accessresources may not be separated by gaps (e.g., PRACH occasions2604E-2604G via freq. 2). Groups of random access resources occasionsmay be separated by gaps (e.g., PRACH occasions 2604H-2604L via freq.3). The random access resources occasions may occur in differentfrequencies (e.g., PRACH occasions 2604A-2604D via freq. 1, PRACHoccasions 2604E-2604G via freq. 2, and/or PRACH occasions 2604H-2604Lvia freq. 3).

Random access resource occasions (e.g., PRACH occasions) may be timedivision multiplexed (TDM-ed) with a guard time (e.g., a time differenceor gap), for example, via Freq 1. A wireless device may perform an LBTprocedure in each random access resource occasion (e.g., PRACH occasion)in a first frequency (e.g., Freq. 1), for example, for multiple preambletransmissions. A wireless device may perform a long LBT procedure and/orshort LBT procedure, for example, depending on the guard time betweentwo random access resource occasions (e.g., PRACH occasions). A wirelessdevice may perform a short LBT procedure (or no LBT procedure) on arandom access resource occasion (e.g., PRACH occasion) available laterthan the other, for example, if the guard time (e.g., time difference)is less than a threshold (25 us, 16 us, or any other duration). Thewireless device may perform a long LBT procedure, for example, if theguard time (e.g., time difference) is greater than or equal to thethreshold. A type of LBT procedure in each random access resourceoccasion (e.g., PRACH occasion) may be configured by an RRC message. Atype of LBT procedure in each random access resource occasion (e.g.,PRACH occasion) may be determined by a wireless device by comparing witha guard time between random access resource occasions (e.g., PRACHoccasions) and the threshold.

One or more random access resource occasions (e.g., PRACH occasions) maybe TDM-ed without a guard time (or less than a threshold), for example,via a second frequency (e.g., Freq 2 in FIG. 26). A wireless device mayperform an LBT procedure on the first random access resource occasion(e.g., PRACH occasion) that occurs firstly among the selected randomaccess resource occasions (e.g., PRACH occasions) via the secondfrequency (e.g., Freq 2). A wireless device may avoid performing an LBTprocedure if the LBT on the first random access resource occasion (e.g.,PRACH occasion) was successful, for example, for subsequent randomaccess resource occasions (e.g., PRACH occasions) followed by the firstrandom access resource occasion (e.g., PRACH occasion) via the secondfrequency (e.g., Freq 2). The LBT procedure on the first random accessresource occasion (e.g., PRACH occasion) may be a long LBT procedure. AnLBT procedure on subsequent random access resource occasions (e.g.,PRACH occasions) may be a short LBT procedure if the LBT on the firstrandom access resource occasion (e.g., PRACH occasion) was successful. Awireless device may perform a long LBT or a short LBT, for example, ifthe selected random access resource occasions (e.g., PRACH occasions)are not contiguous in time. A type of LBT may be configured by a basestation and/or determined based on a time difference of the selectedrandom access resource occasions (e.g., PRACH occasions) that may benon-contiguous. One or more random access resource occasions (e.g.,PRACH occasions) may be grouped without a guard time, for example, via athird frequency (e.g., Freq 3 in FIG. 26). There may be a guard timebetween two groups as shown in random access resource occasion (e.g.,PRACH occasion) f3-2 2604I and random access resource occasion (e.g.,PRACH occasion) f3-3 2604J in FIG. 26. Similar procedures fordetermining an LBT procedure via a second frequency (e.g., Freq. 2) andvia a first frequency (e.g., Freq. 1) may be applied to the groupedPRACH occasions via the first frequency (e.g., Freq. 3), for example,using no LBT procedure, a long LBT procedure, or a short LBT procedure,for example, based on gaps and/or timing.

Using an LBT procedure in an unlicensed spectrum may result in one ormore uplink and/or downlink transmissions being blocked. A wirelessdevice and/or a base station may not transmit any message in a four-stepRA procedure and/or two-step RA procedure, for example, if a channel isbusy (e.g., the channel is determined as occupied by other device(s)based on an LBT procedure).

A wireless device may send (e.g., transmit) at least one preamble (e.g.,RAPs) to a base station on an unlicensed spectrum. A wireless device mayperform one or more LBT procedures (e.g., for preamble transmissions,for example, as described with reference to FIGS. 20-26). The wirelessdevice may transmit at least one preamble to a base station, forexample, if a UL RA channel is idle on an unlicensed spectrum. A basestation may receive at least one preamble that may be transmitted by awireless device. The base station may perform one or more LBT proceduresto transmit at least one downlink control message (e.g., a downlinkmedium access control packet comprising an RAR, a downlink controlsignal) corresponding to the at least one preamble. The base station mayperform a second LBT procedure, for example, if a channel is determinedas busy based on a first LBT procedure. The second LBT procedure may beperformed, for example, after a certain period of time (e.g., backofftime) following the first LBT procedure.

FIG. 27A, FIG. 27B, and FIG. 27C show respectively examples of RAR, MACsubheader with backoff indicator (BI), and a MAC subheader with a RAPID.A wireless device may receive from a base station at least one RAR as aresponse of Msg1 1220 (as shown in FIG. 12) or two-step Msg1 1620 (shownin FIG. 16) using an RA procedure. An RAR may be in a form of MAC PDUcomprising one or more MAC subPDUs and/or (optionally) padding. FIG. 27Ais an example of an RAR. A MAC subheader may be octet-aligned. Each MACsubPDU may comprise one or more of the following: a MAC subheader withBI only; a MAC subheader with RAPID only (e.g., acknowledgment for SIrequest); a MAC subheader with RAPID and MAC RAR. FIG. 27B shows anexample of a MAC subheader with BI. A MAC subheader with BI may compriseone or more header fields (e.g., E/T/R/R/BI) as shown in FIG. 27B anddescribed below. A MAC subPDU with BI may be placed at the beginning ofthe MAC PDU, if included. MAC subPDU(s) with RAPID only, and/or MACsubPDU(s) with RAPID and MAC RAR, may be placed anywhere after a MACsubPDU with BI and, before padding as shown in FIG. 27A. A MAC subheaderwith RAPID may comprise one or more header fields (e.g., E/T/RAPID) asshown in FIG. 27C. Padding may be placed at the end of the MAC PDU, ifpresent. Presence and length of padding may be implicit, for example,based on TB size, and/or a size of MAC subPDU(s).

A field (e.g., an E field) in a MAC subheader may indicate an extensionfield that may be a flag indicating if the MAC subPDU (including the MACsubheader) is the last MAC subPDU or not in the MAC PDU. The E field maybe set to “1” to indicate at least one more MAC subPDU follows. The Efield may be set to “0” to indicate that the MAC subPDU including thisMAC subheader is a last MAC subPDU in the MAC PDU. A field (e.g., a Tfield) may be a flag indicating whether the MAC subheader contains aRAPID or a BI (e.g., one or more backoff values may predefined and BImay indicate one of backoff value). The T field may be set to “0” toindicate the presence of a field (e.g., a BI field) in the subheader.The T field may be set to “1” to indicate the presence of a RAPID fieldin the subheader. A field (e.g., an R field) may indicate a reserved bitthat may be set to “0.” A field (e.g., a BI field) may indicate anoverload condition in the cell. A size of the BI field may be 4 bits. Afield (e.g., a RAPID field) may be a RAPID field that may identifyand/or indicate the transmitted RAP. A MAC RAR may not be included inthe MAC subPDU, for example, based on the RAPID in the MAC subheader ofa MAC subPDU corresponding to one of the RAPs configured for an SIrequest.

There may be one or more MAC RAR formats. At least one MAC RAR formatmay be employed in a four-step or a two-step RA procedure.

FIG. 28 shows an example MAC RAR format. The MAC RAR may be fixed sizeas shown in FIG. 28. The MAC RAR may comprise one or more of thefollowing fields: an R field that may indicate a reserved bit, which maybe set to “0”; a timing advance (TA) command field that may indicate theindex value for TA employed to control the amount of timing adjustment;a UL grant field that indicates the resources to be employed on anuplink; and an RNTI field (e.g., temporary C-RNTI and/or C-RNTI) thatmay indicate an identity that is employed during RA. An RAR may compriseone or more of following for a two-step RA procedure: a UE contentionresolution identity, an RV ID for retransmission of one or more TBs,decoding success or failure indicator of one or more TB transmissions,and one or more fields from the MAC RAR formats.

A base station may multiplex, in a MAC PDU, RARs for two-step and/orfour-step RA procedures. A wireless device may not use an RAR lengthindicator field. The wireless device may determine the boundary of eachRAR in the MAC PDU based on pre-determined RAR size information, forexample, based on RARs for two-step and four-step RA procedures havingthe same size.

FIG. 29 shows an example RAR format. The RAR format may be employed in aMAC PDU, for example, that may multiplex RARs for two-step and four-stepRA procedures. The RAR shown in FIG. 29 may use a fixed size, forexample, using the same format for two-step and four-step RA procedures.

FIG. 30A, and FIG. 30B show example RAR formats. The RAR formats may beemployed for a two-step RA procedure. An RAR for a two-step RA proceduremay have a different format, size, and/or fields, from an RAR for afour-step RA procedure. An RAR may have a field to indicate a type ofRAR (e.g., a reserved “R” field as shown in FIG. 28, for example, basedon RARs for two-step and four-step RA procedures being multiplexed intoa MAC PDU, and/or the RARs having different formats between two-step andfour-step RA procedure). FIG. 30A, and FIG. 30B may be employed toindicate a type of RAR. A field for indicating an RAR type may be in asubheader (such as a MAC subheader) and/or in an RAR. An RAR maycomprise different types of fields that may correspond with an indicatorin a subheader and/or in an RAR. A wireless device may determine theboundary of one or more RARs in a MAC PDU, for example, based on one ormore indicators.

Wireless communications between a base station and one or more wirelessdevices may use various frequencies/frequency bands. Wirelesscommunication between a base station and one or more wireless devicesmay be enhanced, for example, by using one or more expanded frequencybands, such as high frequency bands over 6 GHz (or any other frequency)and/or unlicensed bands. Devices performing wireless communication viahigh frequency bands may experience more communication problems whichmay be due to characteristics of the high frequencies. One or moreunlicensed bands may be occupied by other wireless communicationdevices, and resource allocations and/or resource managements for theunlicensed bands may be more challenging. A wireless device may need toacquire timing synchronization with other communication devices, such asa base station or other wireless devices, more frequently, for example,if the wireless device experiences one or more communication problems(e.g., in high frequency bands and/or the unlicensed bands).

A wireless device may perform one or more access procedures (e.g.,random access procedures) to acquire timing synchronization with a basestation. A wireless device may send a plurality of random accesspreambles via a plurality of channels (e.g., BWPs, beams, SULs, NULs,and/or sub-bands of a BWP). A plurality of PRACH occasions may beallocated across different channels (e.g., BWPs, beams, SULs, NULs,different sub-bands of a BWP, etc.). Wireless devices may gain moreopportunities to perform random access preamble transmissions via aplurality of channels; however, such configurations may increase thecomplexity of the access procedure management for a network (e.g.,comprising one or more base stations). A base station may be expected toreceive more random access preamble transmissions (and/or other accesstransmissions) from a plurality of wireless devices via a plurality ofchannels (e.g., associated with random access). Each wireless device maysend/transmit, to the base station, one or more reports indicating thenumber/quantity of preamble transmissions performed before successfullyreceiving a random access response from the base station and/orindicating whether one or more congestion issues have occurred in arandom access procedure (e.g., in a contention-based random accessprocedure, and/or a contention-free random access procedure). However,such reports may not provide, to the base station, sufficientinformation to determine/identify random access statistics, associatedwith one or more wireless devices, for each channel, for example, if aplurality of channels are allowed for one or more wireless devices forone or more random access procedures.

A wireless device may operate one or more counters associated with aparticular channel to generate channel-specific random access statisticsfor each channel. A wireless device may have a preamble transmissioncounter to count the number/quantity of preamble transmissions via aparticular channel A wireless device may send/transmit, to a basestation, one or more random access reports comprising thechannel-specific random access statistics for at least one channel(e.g., the number/quantity of preamble transmissions via a particularchannel). The base station may better manage and/or allocate randomaccess resources for a plurality of wireless devices, for example, basedon the channel-specific random access statistics. The base station mayoptimize random access procedure channel-by-channel basis, for example,by analyzing the channel-specific random access statistics and theoverall random access statistics for a plurality of channels.

One or more LBT procedures may be performed for one or more randomaccess procedures (e.g., using one or more unlicensed bands). A wirelessdevice may not send/transmit a random access preamble, for example,based on the result of one or more LBT procedures. A random accessprocedure may be delayed, for example, if the wireless device does notsend/transmit a preamble via a random access resource based on theresult of the one or more LBT procedures. However, a base station maynot be aware of one or more delays caused by the dropped (canceled,delayed, skipped, and/or aborted) preamble transmissions due to the oneor more LBT procedures.

A wireless device may operate one or more counters associated with oneor more LBT procedures. A wireless device may have a preambletransmission attempt counter to count the number/quantity of LBTperformed for one or more random access procedure. A wireless device maysend/transmit, to a base station, one or more random access reportscomprising the LBT performance statistics (e.g., the number/quantity ofLBT performed for one or more random access procedure). The one or morecounters associated with one or more LBT procedures may bechannel-specific. A wireless device may have a channel-specific preambletransmission attempt counter to count the number/quantity of LBTperformed on a particular channel for one or more random accessprocedure. A wireless device may send/transmit, to a base station, oneor more random access reports comprising the channel-specific LBTperformance statistics (e.g., the number/quantity of LBT performed on aparticular channel for one or more random access procedures).

A base station and/or a wireless device may experience more signalingoverhead burden, for example, if more types of random access statisticsare communicated between each other. To reduce/avoid one or morepossible signaling overhead problems, a base station may triggerdifferent types of random access reporting. A base station may send, toone or more wireless devices, one or more request for random accessreports comprising an indication of one or more types of random accessstatistics (e.g., random access statistics associated with a firstsub-band of a particular BWP, LBT performance statistics associated witha second sub-band of a particular BWP, etc.). One or more reporting-typeindicators may indicate a per-cell based reporting, a per-channel basedreporting, or both. A base station may flexibly determine which types ofstatistics are needed and may request different types of random accessreports from one or more wireless devices. These configurations mayincrease the flexibility of random access reporting and reduce signalingoverhead.

A base station may instruct one or more wireless device (e.g., one ormore wireless devices or sensors connected to a power source, such as apower outlet) to periodically report one or more random access reports.The periodic reporting may be configured semi-statically bysending/transmitting one or more messages (e.g., an RRC message). One ormore control messages (e.g., a DCI or a MAC CE) indicating an activationor deactivation of the random access reporting may be sent, from thebase station to one or more wireless devices, to activate or deactivatethe periodic random access reporting.

An enhanced congestion resolution for random access procedures of aplurality of wireless devices may be provided, for example, based on oneor more enhanced random access reporting procedures. The random accessstatistics and/or the LBT performance statistics may be generated by oneor more wireless devices at a per-cell level and/or a per-channel level.A random access contention resolution problem may be reported at aper-channel level. A network may better optimize one or more randomaccess procedures for a plurality of wireless devices. A base stationmay control and optimize one or more random access parameters (e.g.,back-off parameters) channel-by-channel basis, for example, based on oneor more types of channel-specific random access statistics provided by aplurality of wireless devices.

A wireless device may perform an access procedure (e.g., a random accessprocedure) with a base station. The access procedure (e.g., randomaccess procedure) may comprise one or more retransmissions. A wirelessdevice may perform/send one or more (re)transmissions of one or morepreambles during a random access procedure. The wireless device maydetermine the one or more retransmissions of one or more preambles basedon one or more conditions. The wireless device may determine the one ormore retransmissions of one or more preambles, for example, if thewireless device determines that a random access response reception isnot successful. The wireless device may determine that a random accessresponse reception is not successful, for example, if at least onerandom access response, comprising one or more random access preambleidentifiers that matches the transmitted PREAMBLE_INDEX, has not beenreceived at least until an RAR window (e.g., ra-ResponseWindowconfigured in RACH-ConfigCommon) expires. The wireless device maydetermine that a random access response reception is not successful, forexample, if a PDCCH addressed to the C-RNTI has not been received viathe serving cell via which the preamble was sent/transmitted at leastuntil an RAR window for beam failure recovery (e.g., ra-ResponseWindowconfigured in BeamFailureRecoveryConfig) expires.

A wireless device may determine the one or more retransmissions of oneor more preambles, for example, if the wireless device determines that acontention resolution is not successful. The wireless device (e.g., aMAC entity of the wireless device) may start a contention resolutiontimer (e.g., ra-ContentionResolutionTimer) and/or may restart thecontention resolution timer (e.g., ra-ContentionResolutionTimer) at eachHARQ retransmission in the first symbol after the end of a Msg3transmission. The MAC entity of the wireless device may start or restartthe contention resolution timer, for example, after the wireless devicesends/transmits, to a base station, the Msg3. The wireless device maymonitor a PDCCH, for example, at a time that the contention resolutiontimer (e.g., ra-ContentionResolutionTimer) is running (e.g., regardlessof the possible occurrence of a measurement gap). A wireless device maystop the contention resolution timer and determine that a contentionresolution is successful, for example, if a notification of a receptionof a PDCCH transmission of a cell (e.g., an SpCell) is received from oneor more lower layers, and/or if the wireless devicedetermines/identifies that the PDCCH transmission is an indication of acontention resolution corresponding to a Msg3 transmission (or MsgBtransmission) performed by the wireless device.

A wireless device may determine one or more retransmission of one ormore preambles, for example, if the wireless device determines that acontention resolution is not successful. A wireless device may determinethat a contention resolution is not successful, for example, if thewireless device does not receive an indication of a contentionresolution at a time that a contention resolution timer (e.g.,ra-ContentionResolutionTimer) is running. The wireless device maydetermine that a contention resolution is not successful, for example,if the contention resolution timer (e.g., ra-ContentionResolutionTimer)expires. The wireless device may discard a temporary C-RNTI (e.g.,TEMPORARY_C-RNTI) that may be indicated by an RAR, for example, after orin response to an expiry of the contention resolution timer (and/or thecontention resolution being unsuccessful).

A wireless device may determine one or more retransmissions of one ormore preambles, for example, for a two-step RA procedure, if thewireless device does not receive a MsgB corresponding to a MsgA during awindow configured to monitor MsgB in one or more DL control channels. Awireless device performing a two-step RA procedure may receive aresponse (e.g., MsgB) indicating a fallback to a four-step RA procedure.The wireless device may start a timer (e.g.,ra-ContentionResolutionTimer), for example, after or in response totransmitting one or more TBs (e.g., Msg3) to a base station. Thewireless device may determine one or more retransmissions of one or morepreambles, for example, if the timer (e.g.,ra-ContentionResolutionTimer) expires.

A wireless device be determine a quantity/number of transmissions (e.g.,preamble transmissions) during an access procedure (e.g., a randomaccess procedure). A wireless device may adjust/increment a counter forcounting a quantity/number of preamble transmissions (e.g.,PREAMBLE_TRANSMISSION_COUNTER) by 1 (or another value), for example,based on or in response to a random access response reception beingunsuccessful and/or a contention resolution being unsuccessful. Thewireless device may determine that a random access procedure isunsuccessfully completed and/or a MAC entity of the wireless device mayindicate a random access problem to upper layer(s), for example, if thequantity/number of preamble transmissions satisfy (e.g., reach) athreshold (e.g., if PREAMBLE_TRANSMISSION_COUNTER=preambleTransMax+1).The wireless device may determine that a random access procedure (and/orone or more retransmissions of one or more preambles) is not completed,for example, if the number/quantity of preamble transmissions does notsatisfy (e.g., reach) a threshold, (e.g., ifPREAMBLE_TRANSMISSION_COUNTER <preambleTransMax+1).

A wireless device may delay a retransmission of a preamble for aparticular period of time (e.g., a backoff time) associated with aretransmission of one or more preamble. The wireless device may set thebackoff time to 0 ms (or any other time duration), for example, if arandom access procedure is initiated. The wireless device may set (orupdate) the backoff time, for example, based on a preamble backoff(e.g., PREAMBLE_BACKOFF) that may be determined by a value in a BI fieldof the MAC subPDU (e.g., BI field in FIG. 27B). The wireless device mayset the preamble backoff (e.g., PREAMBLE_BACKOFF) to a value of the BIfield of the MAC subPDU using a predefined table. The predefined tablemay comprise backoff parameter value(s). BI may indicate one of thebackoff parameter values. The wireless device may set the preamblebackoff (e.g., PREAMBLE_BACKOFF) to 30 ms (or any other time duration),for example, if the wireless device receives BI indicating index 3 (or0010 in a bit string) and the index 3 is associated with 30 ms (or anyother time duration) in the table. The wireless device may set thepreamble backoff (e.g., PREAMBLE_BACKOFF) to a value of the BI field ofthe MAC subPDU multiplied by a scaling factor (e.g., SCALING_FACTOR_BI),for example, if a base station configures the wireless device with ascaling factor (e.g., scalingFactorBI) by one or more RRC messages.SCALING_FACTOR_BI and scalingFactorBI may have the same value,scalingFactorBI may be configured by a base station for the wirelessdevice. The wireless device may receive a message indicatingscalingFactorBI and may store the value of scalingFactorBI as the valueof SCALING_FACTOR_BI. The value of SCALING_FACTOR_BI may be maintainedand may be used by the wireless device, for example, for multiplying thescaling factor (e.g., SCALING_FACTOR_BI) with the value of the BI field.The wireless device may set (or update) the preamble backoff (e.g.,PREMABLE_BACKOFF) based on a BI field, for example, if a downlinkassignment has been received via the PDCCH for the RA-RNTI and thereceived TB is successfully decoded, and/or if the random accessresponse comprises a MAC subPDU with a backoff indicator (e.g., BI inFIG. 27B). The wireless device may set the preamble backoff (e.g.,PREAMBLE_BACKOFF) to 0 ms, for example, if a downlink assignment has notbeen received via the PDCCH for the RA-RNTI and/or the received TB isnot successfully decoded, and/or if the random access response does notcomprise a MAC subPDU with a backoff indicator (e.g., BI in FIG. 27B).

A wireless device may determine a backoff time, for example, based onthe preamble backoff (e.g., PREAMBLE_BACKOFF). The wireless device maydetermine the backoff time, for example, if the wireless devicedetermines that a random access response is not successfully receivedand/or a contention resolution is not successful. The wireless devicemay use a particular determination/selection mechanism todetermine/select the backoff time. The wireless device maydetermine/select the backoff time, for example, based on a uniformdistribution between 0 and the preamble backoff (e.g.,PREAMBLE_BACKOFF). The wireless device may use other types ofdistribution to determine/select the backoff time based on the preamblebackoff (e.g., PREAMBLE_BACKOFF).

The wireless device may ignore the preamble backoff (e.g.,PREAMBLE_BACKOFF, a value in BI field in FIG. 27B, etc.) and/or may nothave a backoff time. The wireless device may determine whether to applythe backoff time to a retransmission of at least one preamble, forexample, based on an event type initiating the random access procedure(e.g., a beam failure recovery request, handover, etc.) and/or a type ofthe random access procedure (e.g., four-step or two-step RA and/orcontention-based RA (CBRA) or contention-free RA (CFRA)). The wirelessdevice may apply the backoff time to the retransmission, for example, ifthe random access procedure is CBRA (e.g., in which a preamble may beselected by the wireless device or a MAC entity of the wireless device)and/or if the wireless device determines that a random access procedureis not completed based on a random access response reception beingunsuccessful. The wireless device may apply the backoff time to theretransmission, for example, if the wireless device determines that arandom access procedure is not completed based on a contentionresolution being unsuccessful.

A wireless device may perform a random access resource selectionprocedure (e.g., select at least one SSB or CSI-RS and/or select PRACHcorresponding to at least one SSB or CSI-RS selected by the wirelessdevice), for example, if the random access procedure is not completed.The wireless device may delay the subsequent random access preambletransmission (or delay a random access resource selection procedure) forthe backoff time.

A wireless device may change/switch a channel (e.g., a BWP and/or asubband) to send/transmit at least one preamble for a retransmission.The change/switch may increase the quantity/number of preambletransmission opportunities. A base station may send/transmit, to awireless device, one or more messages (e.g., broadcast messages and/orRRC messages) indicating a configuration of the one or more channels(e.g., BWPs, transmission/reception beams, SSBs, and/or subbands) forwhich one or more PRACHs may be configured. A wireless device maydetermine/select one of the one or more channels (e.g., BWPs and/orsubbands) as a channel (e.g., a BWP, a transmission/reception beam, anSSB, and/or a subband) to send/transmit a first preamble. The wirelessdevice may determine/select the channel (e.g., BWP and/or subband) basedon an LBT procedure result. The wireless device may perform one or moreLBT procedures on one or more channels. The wireless device maydetermine/select the channel among the channel(s) being determined(e.g., sensed) as idle. The wireless device may determine/select one ofthe channels being determined as idle, for example, based on a randomselection.

The channel may be determined/defined based on a BWP configuration, asubband configuration, and/or another wireless resource configuration. Abase station may configure a wireless device with one or more initial DLBWPs and/or UL BWPs. A configuration of each of the one or more initialDL BWPs and/or UL BWPs may comprise a dedicated DL BWP (e.g.,BWP-DownlinkDedicated) (e.g., for an initial DL BWP) and/or a dedicatedUL BWP (e.g., BWP-UplinkDedicated) (e.g., for an initial UL BWP)configurations. The dedicated DL BWP configurations and/or the dedicatedUL BWP configurations may indicate at least one of the following: asubcarrier spacing, a cyclic prefix, a location and a bandwidth of eachof the one or more initial DL and/or UL BWPs, a DL control channelconfiguration, a DL shared channel configuration, a rach-configuration(e.g., rach-ConfigCommon and/or rach-ConfigDedicated), a UL controlconfiguration, and/or a UL shared channel configuration.

One of (e.g., initial) UL BWP(s) may be associated with at least one of(e.g., initial) DL BWP(s). The association may be indicated byconfiguration parameter(s) in the one or more messages transmitted bythe base station and/or may be predefined. The association may bedetermined/set, for example, by a (e.g., initial) UL BWP configuration(or an (e.g., initial) DL BWP configuration) that may comprise a DL BWPindex of one of one or more DL BWPs and/or a UL BWP index of one of oneor more UL BWPs. The association may be determined/set by a predefinedrule and/or a table. A (e.g., initial) UL BWP may have an associationwith a (e.g., initial) DL BWP that may have the same BWP index (e.g., ULBWP #0 with DL BWP #0, UL BWP #1 with DL BWP #1, and so on). A wirelessdevice may monitor, for a random access response, a control channel, forexample, based on the association. A wireless device may monitor, for arandom access response, a control channel of a (e.g., initial) DL BWPassociated with a (e.g., initial) UL BWP via which the wireless devicesends/transmits at least one preamble. A wireless device may monitor,for a contention resolution, a control channel of a (e.g., initial) DLBWP associated with a (e.g., initial) UL BWP via which the wirelessdevice transmits Msg3.

A wireless device may receive, from a base station, an RRC messageindicating the association between one of (e.g., initial) UL BWP(s) andleast one of (e.g., initial) DL BWP(s). A serving cell configuration(e.g., ServingCellConfigCommon or ServingCellConfigCommonSIB) in the RRCmessage may indicate a BWP configuration (e.g., DownlinkConfigCommon orDownlinkConfigCommonSIB for the initial DL BWP and/orUplinkConfigCommonSIB for the initial uplink BWP) for a random accessprocedure. One or more DL/UL BWP pairs may be configured. Each DL/UL BWPpair may comprise at least one (e.g., initial) DL BWP configuration andone or more (e.g., initial) UL BWP configuration. One (e.g., initial) DLBWP configuration and one or more (e.g., initial) UL BWP configurationmay be paired. The RRC message (and/or the one (e.g., initial) DL BWPconfiguration and/or the serving cell configuration) may compriseparameters indicating one or more transmissions of one or more SSBs (orCSI-RSs). The one or more SSBs may be configured per a BWP (e.g., viathe one (e.g., initial) DL BWP configuration) and/or per a cell (e.g.,via the serving cell configuration). One or more PRACH resourcesconfigured in the one or more (e.g., initial) UL BWP configurations maybe associated with the one or more SSBs. A wireless device mayswitch/change/select a UL BWP for a preamble retransmission among theone or more UL BWPs associated with the one (e.g., initial) DL BWPconfiguration, for example, if the wireless device determines/selectsone of the one or more SSBs. A wireless device may determine/selectPRACH resource(s) configured in one or more (e.g., initial) UL BWPsassociated with one or more (e.g., initial) DL BWPs. The wireless devicemay determine/select PRACH resource(s) configured in one or more (e.g.,initial) UL BWPs associated with one or more (e.g., initial) DL BWPs,for example, if a wireless device determines/selects one or more SSBsfrom the one or more (e.g., initial) DL BWPs.

A wireless device and/or a base station may perform an LBT procedure,for example, before sending/transmitting each message (e.g., Msg1, Msg2,Msg3, Msg4, MsgA, and/or MsgB) via an unlicensed band. Each messagetransmission attempt may experience an LBT failure that may cause arandom access delay/latency. A large delay/latency during a randomaccess procedure may not satisfy a control plane requirement. Increasingtransmission opportunities configured over a frequency domain (e.g.,over one or more channels, BWPs and/or subbands) may enhance therobustness of the random access procedure (e.g., improve the randomaccess delay/latency caused by an LBT failure in an unlicensed band).

A base station may configure a wireless device with a plurality ofchannels (e.g., a plurality of DL and/or UL BWPs and/or subbands). For aMsg1 (e.g., MsgA) transmission, the wireless device may attempt toperform an LBT procedure in one or more UL BWPs configured with RACHresource(s). The wireless device may perform a Msg1 (e.g., MsgA)transmission via RACH resource(s) in a UL BWP, for example, if at leastone LBT procedure is successful on the UL BWP. The probability of LBTsuccess may increase, for example, if each channel status of the one ormore UL BWPs is independent of each other.

For Msg2/Msg4 (or MsgB) enhancement, a base station may attempt toperform at least one LBT on a plurality of DL BWPs. The base station mayperform a Msg2/Msg4 (MsgB) transmission, for example, if an LBTprocedure is successful. A wireless device may monitor a PDCCH in one ormore DL BWPs of the plurality of DL BWPs. The one or more DL BWPs may beassociated with one or more UL BWPs via which the wireless device maysend/transmit at least one of Msg1, Msg3 and/or MsgB. The one or more DLBWPs may be predefined and/or semi-statically configured by an RRCmessage transmitted by the base station.

For Msg3 enhancement, a base station may send/transmit at least one RARcomprising a plurality of UL grants corresponding to a plurality ofBWPs. Each of the UL grants may comprise one or more fields indicating aBWP identifier and/or a time/frequency domain resource in a BWPcorresponding to the BWP identifier. The wireless device may perform atleast one LBT procedure on one or more of indicated BWPs (e.g., theplurality of BWPs). The wireless device may perform a Msg3 transmission,for example, if an LBT procedure is successful.

A wireless device may send (e.g., transmit) Msg1 and Msg3 via differentchannels (e.g., UL BWPs and/or subbands). A wireless device may receiveMsg2 and Msg4 via different channels (e.g., DL BWPs and/or subbands). Awireless device may send/transmit Msg1 for a preamble retransmission viaa channel (e.g., a UL BWP and/or a subband). The channel may bedifferent from a channel via which the wireless device transmitted Msg1in a previous preamble (re)transmission.

A base station may configure multiple preamble transmissionopportunities over a frequency domain (e.g., in a frequency band of aradio access technology, such as LTE LAA, NR unlicensed, and/or anyother access technology). A wireless device may select a different ULBWP (e.g., a different subband) during one or more retransmissions(e.g., comprising an initial transmission) of at least one preamble. Awireless device may send/transmit a first preamble via a first PRACH ina first BWP (or a first subband) for a first (re)transmission during anRA procedure. The wireless device may send/transmit a second preamblevia a second PRACH in a second BWP (or a second subband) for a second(re)transmission during the RA procedure. The first BWP (or subband) maybe different from the second BWP (or subband), for example, depending onone or more LBT procedure results on the first and second BWPs (orsubbands). The first BWP (or subband) and the second BWP (or subband)may be the same, for example, depending on one or more LBT procedureresults on the first and second BWPs (or subbands).

FIG. 31 shows an example of one or more preamble transmissionopportunities. The one or more preamble transmission opportunities maybe configured via one or more channels (e.g., BWPs, subbands, unlicensedbands, and/or other channels). A base station may send (e.g., transmit)one or more RRC messages indicating one or more PRACH resources for oneor more preamble transmission opportunities on one or more channels(e.g., BWPs, subbands, etc.). The wireless device may determine/selectat least one PRACH (and/or at least one BWP or subband) for at least onepreamble transmission. The wireless device may determine/select adifferent PRACH (and/or different BWP or subband), for example, if thewireless device performs a preamble retransmission. An LBT procedureresult may be used for a selection of PRACH. A wireless device mayperform one or more LBT procedures before determining/selecting one ormore PRACHs (e.g., PRACH 3110, PRACH 3120, PRACH 3130, and PRACH 3140).The wireless device may send/transmit at least one preamble via at leastone PRACH (e.g., on BWP and/or subband) in which a corresponding LBTprocedure is successful. The wireless device may determine a pluralityof preamble transmission opportunities over one or more PRACHs (e.g.,PRACH 3110, PRACH 3130). The wireless device may determine/select one ofthe one or more PRACHs, for example, based on a random selection. Thewireless device may determine a retransmission of at least one preamble,for example, if the wireless device determines that a reception of anRAR is not successful and/or a contention resolution is not successful.The wireless device may determine one or more preamble transmissionopportunities over one or more PRACHs (e.g., PRACH 3160, PRACH 3180)that may be configured in different channel(s) (e.g., BWP(s) orsubband(s)).

A wireless device may delay a retransmission of a preamble based on abackoff time. A BI (e.g., the BI in FIG. 27B) may be set for a UL BWP(e.g., an initial UL BWP) configured for a random access procedure(e.g., configured in a SIB1 IE), for example, in a legacy system. Thequantity/number of the UL BWP(s) (e.g., the initial UL BWP(s)) may be atmost one (e.g., in at least some legacy or other systems). A basestation may configure multiple preamble transmission opportunities overa frequency domain (e.g., in a frequency band of a radio accesstechnology, such as LTE LAA, NR unlicensed, or any other accesstechnology). A wireless device may determine/select a different UL BWP(or a different subband), for example, for each time of one or moreretransmissions (e.g., comprising an initial transmission) of at leastone preamble. One or more backoff times for one or more (e.g., initial)UL BWPs (or subbands) on which one or more PRACHs are configured may beset and managed.

A wireless device may send/transmit one or more preambles during an RAprocedure. The wireless device may determine to transmit the one or morepreambles, for example, based on or in response to determining apreamble retransmission. The wireless device may determine the preambleretransmission, for example, based on or in response to an RAR receptionbeing completed unsuccessfully and/or a contention resolution beingcompleted unsuccessfully. The wireless device may determine tosend/transmit the one or more preambles to increase the quantity/numberof transmission opportunities (e.g., to increase a success probabilityof a preamble transmission). The wireless device may send/transmit theone or more preambles for a particular type of RA procedure (e.g., CBRAand/or CFRA), and/or for a particular type of event(s) initiating the RAprocedure (e.g., an SCell addition, a handover, a beam failure recovery,etc.). The wireless device may determine to send/transmit the one ormore preambles in a particular frequency. The wireless device maysend/transmit the one or more preambles via an unlicensed band. A basestation may send/transmit, to a wireless device, a message (e.g., a SIB,an RRC message, and/or a control signal) indicating one or more PRACHsconfigured in time and/or frequency domain. The wireless device maysend/transmit the one or more preambles via at least one of the one ormore PRACHs. The wireless device may perform one or more LBT procedures,for example, before sending/transmitting at least one of the one or morepreambles via the at least one of the one or more PRACHs in anunlicensed band.

A wireless device may manage one or more counters indicating aquantity/number of preamble transmissions (e.g.,PREAMBLE_TRANSMISSION_COUNTER) and/or a quantity/number of preambletransmission attempts (e.g., PREAMBLE_TRANSMISSION_ATTEMPT_COUNTER orPREAMBLE_ATTEMPT_COUNTER) for an RA procedure.PREAMBLE_TRANSMISSION_COUNTER may count the quantity/number of preambletransmissions performed during the RA procedure. A counter (e.g.,PREAMBLE_ATTEMPT_COUNTER) may be used to count the quantity/number ofpreamble transmission attempts performed during the RA procedure. Thewireless device may count the quantity/number of preamble transmissionattempts via an unlicensed band. The wireless device may count thequantity/number of LBT procedures performed during the RA procedure asthe quantity/number of preamble transmission attempts. The wirelessdevice may increment a counter (e.g., PREAMBLE_ATTEMPT_COUNTER), basedon or in response to performing the LBT procedure, regardless of whetheror not a preamble transmission occurs.

In an RA procedure via an unlicensed band, a base station and/or awireless device may determine value(s) of one or more counters (e.g.,PREAMBLE_TRANSMISSION_COUNTER and/or PREAMBLE_ATTEMPT_COUNTER), forexample, based on one or more LBT procedures. A wireless device mayperform an LBT procedure for a preamble transmission via a PRACH. Thewireless device may increment an attempt counter (e.g.,PREAMBLE_ATTEMPT_COUNTER) by one (or another value), for example, if thewireless device performs the LBT procedure. The wireless device mayincrement a transmission counter (e.g., PREAMBLE_TRANSMISSION_COUNTER)by one (or another value), for example, if the wireless devicesends/transmits a preamble via the PRACH and/or if a (e.g., actual orphysical) transmission of the preamble occurs. The wireless device maysend/transmit the preamble, for example, based on or in response to thePRACH being determined (e.g., sensed) as idle based on the LBTprocedure. The wireless device may not increment the transmissioncounter (e.g., PREAMBLE_TRANSMISSION_COUNTER), for example, if apreamble transmission is dropped/canceled/delayed/skipped/aborted due toan LBT failure. The wireless device may increment the attempt counter(e.g., PREAMBLE_ATTEMPT_COUNTER), for example, regardless of whether apreamble transmission occurs and/or regardless of whether or not apreamble transmission is dropped/canceled/delayed/skipped/aborted due toan LBT failure.

A wireless device (e.g., a MAC layer of a wireless device) may determineat least one preamble transmission (e.g., determine a random accessresource selection comprising determining a preamble index, PRACHoccasion(s), etc.). The wireless device (e.g., MAC layer of the wirelessdevice) may indicate (or instruct), to a PHY layer of the wirelessdevice, to send/transmit at least one preamble via a PRACHdetermined/selected by the MAC layer. The wireless device (e.g., the PHYlayer of the wireless device) may perform at least one LBT procedure onthe PRACH. The wireless device (e.g., the PHY layer of the wirelessdevice) may determine whether to send/transmit the at least onepreamble, for example, based on an outcome of the at least one LBTprocedure. The wireless device (e.g., the PHY layer of the wirelessdevice) may drop/cancel/delay/skip/abort a transmission of the at leastone preamble, for example, if the at least one LBT procedure has failed(e.g., the at least one LBT procedure indicates that the PRACH is notidle). The wireless device (e.g., the PHY layer of the wireless device)may perform a transmission of the at least one preamble, for example, ifthe at least one LBT procedure is successful (e.g., the at least one LBTindicates that the PRACH is idle). The wireless device (e.g., the PHYlayer of the wireless device) may indicate, to a MAC layer (e.g., a MACentity), whether the LBT procedure has failed or is successful, and/orwhether or not the at least one preamble is transmitted. The wirelessdevice (e.g., the MAC layer of the wireless device) may determine thequantity/number of preamble transmissions and/or the number of preambletransmission attempts (e.g., to determine whether to incrementPREAMBLE_TRANSMISSION_COUNTER and/or PREAMBLE_ATTEMPT_COUNTER) based onthe LBT failure/success indicator.

FIG. 32 shows an example of counter operations. A wireless device mayattempt to send/transmit one or more preambles via one or more channels(BWPs and/or subbands). A first counter may be used to count thequantity/number of preamble transmission attempts (e.g.,PREAMBLE_ATTEMPT_COUNTER). The wireless device may increment a value ofthe first counter, for example, based on or in response to performing anLBT procedure. A second counter may be used to count the quantity/numberof preamble transmissions (e.g., PREAMBLE_TRANSMISSION_COUNTER). Forexample, the wireless device may increment a value of the secondcounter, for example, based on or in response to transmitting at leastone preamble.

The quantity/number of preamble transmissions and the number of preambletransmission attempts may be counted in one or more ways. A wirelessdevice may send (e.g., transmit) a plurality of preambles (e.g., beforestarting ra-ResponseWindow or before an expiry of ra-ResponseWindowstarted based on or in response to sending/transmitting at least one ofthe plurality of preambles. The wireless device may count/determine thequantity/number of the plurality of sent/transmitted preambles. Thewireless device may add the quantity/number of the plurality ofsent/transmitted preambles to a transmission counter (e.g.,PREAMBLE_TRANSMISSION_COUNTER). The wireless device may determine/counta second quantity/number of a second plurality of sent/transmittedpreambles. The wireless device may add the second number to atransmission counter (e.g., PREAMBLE_TRANSMISSION_COUNTER), for example,if the wireless device determines a preamble retransmission andsends/transmits the second plurality of preambles.

A wireless device may control/manage a third counter (e.g.,PREAMBLE_RETRANSMISSION_COUNTER) for determining/counting thequantity/number of (re)transmission in an RA procedure. The wirelessdevice may set the third counter (e.g., PREAMBLE_RETRANSMISSION_COUNTER)to a predefined (or initial) value (e.g., zero), for example, if thewireless device initiates the RA procedure. The wireless device mayincrement the third counter (e.g., PREAMBLE_RETRANSMISSION_COUNTER) byone (or any other value), for example, based on or in response todetermining that the RA procedure is not complete (e.g., based on an RARreception being unsuccessful and/or a contention resolution beingunsuccessful). The wireless device may determine whether or not the RAprocedure is unsuccessfully completed at least based on third counter(e.g., PREAMBLE_RETRANSMISSION_COUNTER). The wireless device maydetermine that the RA procedure is unsuccessfully completed, forexample, if the third counter (e.g., PREAMBLE_RETRANSMISSION_COUNTER) isequal to or greater than a threshold (e.g., preambleReTrnasMax+1, wherepreambleReTrnasMax may be predefined or semi-statically configured by abase station). The wireless device may determine to perform a preambleretransmission, for example, if the third counter (e.g.,PREAMBLE_RETRANSMISSION_COUNTER) is less than the threshold (e.g., apreamble retransmission threshold).

As shown in FIG. 32, a wireless device may have a plurality of PRACH(e.g., PRACH occasions) during the n-th (re)transmission opportunity fortransmitting a preamble. The wireless may perform an LBT procedure 3202a, may determine that the PRACH 3204 a is not idle, and/or may determineto drop/cancel/delay/skip/abort a preamble transmission on the PRACH3204 a. Based on the performance of the LBT procedure 3202 a, thewireless device may increment the first counter by one (or anothervalue). The wireless may perform an LBT procedure 3202 b, may determinethat the PRACH 3204 b is idle, and/or may send/transmit a preamble(e.g., the n-th preamble transmission) via the PRACH 3204 b. Based onthe performance of the LBT procedure 3202 b, the wireless device mayfurther increment the first counter by one (or another value). Based onthe transmission of the preamble via the PRACH 3204 b, the wirelessdevice may increment the second counter by one (or another value).

The wireless device may monitor an RAR during an RAR window, forexample, based on or in response to sending/transmitting the preamblevia the PRACH 3204 b. The wireless device may determine that thewireless device has not received an RAR responsive to the preamble sentvia the PRACH 3204 b, for example, if the wireless device does notreceive an RAR during the RAR window, fails to detect an RAR, and/orreceives an RAR associated with another wireless device. The wirelessdevice may determine whether to perform a retransmission of at least onepreamble, for example, after determining that the wireless device hasnot received the RAR responsive to the preamble sent via the PRACH 3204b. The wireless device may increment the third counter by one, forexample, after determining to perform a retransmission (e.g., n+1-th(re)transmission) of at least one preamble.

A wireless device may have a plurality of PRACHs (e.g., PRACH occasions)during the n+1-th (re)transmission opportunity for transmitting apreamble. The wireless may perform an LBT procedure 3202 c, maydetermine that the PRACH 3204 c is idle, and/or may send/transmit apreamble (e.g., the n+1-th preamble transmission) via the PRACH 3204 c.Based on the performance of the LBT procedure 3202 c, the wirelessdevice may further increment the first counter by one (or anothervalue). Based on the transmission of the preamble via the PRACH 3204 c,the wireless device may further increment the second counter by one (oranother value).

FIG. 33 shows an example of counter operations. A wireless device mayattempt to send/transmit one or more preambles via one or more channels(e.g., BWP and/or subbands). A first counter may be used tocount/determine the quantity/number of preamble transmission attempts(e.g., PREAMBLE_ATTEMPT_COUNTER). The wireless device may increment avalue of the first counter, for example, based on or in response toperforming an LBT procedure. A second counter may be used tocount/determine the quantity/number of preamble transmissions (e.g.,PREAMBLE_TRANSMISSION_COUNTER). The second counter may be used to counta total quantity/number of preamble transmissions. The wireless devicemay increment a value of the second counter, for example, based on or inresponse to sending/transmitting at least one preamble. A third countermay be used to count the quantity/number of (re)transmissions (e.g.,PREAMBLE_RETRANSMISSION_COUNTER) The wireless device may increment avalue of the third counter, for example, based on or in response todetermining a retransmission of at least one preamble (e.g., determining(n+1)-th (re)transmission shown in FIG. 33).

As shown in FIG. 33, a wireless device may have a plurality of PRACHs(e.g., PRACH occasions) during the n-th (re)transmission opportunity forsending/transmitting a preamble. The wireless may perform an LBTprocedure 3302 a, may determine that the PRACH 3304 a is not idle,and/or may determine to drop/cancel/delay/skip/abort a preambletransmission on the PRACH 3304 a. Based on the performance of the LBTprocedure 3302 a, the wireless device may increment the first counter byone (or any other value). The wireless may perform an LBT procedure 3302b, may determine that the PRACH 3304 b is idle, and/or may transmit apreamble via the PRACH 3304 b. Based on the performance of the LBTprocedure 3302 b, the wireless device may further increment the firstcounter by one (or any other value). Based on the transmission of thepreamble via the PRACH 3304 b, the wireless device may increment thesecond counter by one (or any other value). The wireless may perform anLBT procedure 3302 c, may determine that the PRACH 3304 c is idle,and/or may send/transmit a preamble via the PRACH 3304 c. Based on theperformance of the LBT procedure 3302 c, the wireless device may furtherincrement the first counter by one (or any other quantity). Based on thetransmission of the preamble via the PRACH 3304 c, the wireless devicemay further increment the second counter by one.

The wireless device may monitor an RAR during an RAR window, forexample, based on or in response to sending/transmitting the preamblevia the PRACH 3204 c. The wireless device may determine that thewireless device has not received an RAR responsive to at least one ofthe preambles (e.g., the preamble transmission via the PRACH 3304 b, thepreamble transmission via the PRACH 3304 c, etc.) sent during the n-th(re)transmission window, for example, if the wireless device does notreceive an RAR during the RAR window, fails to detect an RAR, and/orreceives an RAR associated with another wireless device. The wirelessdevice may determine whether to perform a retransmission of at least onepreamble, for example, after determining that the wireless device hasnot received the RAR responsive to the preamble sent via the PRACH 3304b (e.g., during an RAR window associated with the PRACH 3304 b). Thewireless device may determine to perform the LBT procedure 3302 c, forexample, after or in response to determining that the wireless devicehas not received an RAR responsive to the preamble sent/transmitted viathe PRACH 3304 b. The wireless device may send/transmit the preamble viathe PRACH 3304 c, for example, after or in response to the LBT procedure3302 c. The wireless device may determine that the wireless device hasnot received the RAR responsive to the preamble sent via the PRACH 3304c (e.g., during an RAR window associated with the PRACH 3304 c). Thewireless device may increment a third counter by one (or any othervalue), for example, after determining to perform a retransmission(e.g., n+1-th (re)transmission) of at least one preamble.

A wireless device may have a plurality of PRACHs (e.g., PRACH occasions)during the n+1-th (re)transmission opportunity for transmitting apreamble. The wireless may perform an LBT procedure 3302 d, maydetermine that the PRACH 3304 d is idle, and/or may send/transmit apreamble via the PRACH 3304 d. Based on the performance of the LBTprocedure 3302 d, the wireless device may further increment the firstcounter by one (or any other value). Based on the transmission of thepreamble via the PRACH 3304 d, the wireless device may further incrementthe second counter by one (or any other value).

A base station may configure a wireless device with one or more channelscomprising one or more PRACHs for an RA procedure. The wireless devicemay attempt to send/transmit at least one preamble in different channelsof the one or more channels. The wireless device may attempt tosend/transmit at least one preamble in a same channel (e.g., a BWP or asubband). The wireless device may switch to a different channel, forexample, based on or in response to determining a preambleretransmission. The channel switching may occurretransmission-by-retransmission (e.g., in response to determining apreamble retransmission due to an RAR reception and/or a contentionresolution being unsuccessful).

FIG. 34 shows an example of channel switching. A base station maysend/transmit a message comprising configuration parameters indicatingone or more PRACHs (e.g., for an RA procedure in an unlicensed band). Awireless device may attempt to send/transmit one or more first preamblesin channel A. The wireless device may perform one or more first LBTprocedures to determine whether to send/transmit the one or more firstpreambles via channel A. As shown in FIG. 34, during an n-th(re)transmission opportunity, a wireless device may perform an LBTprocedure 3402 a, may determine that the PRACH 3404 a is not idle,and/or may determine to drop/cancel/delay/skip/abort a preambletransmission on the PRACH 3404 a. During the n-th (re)transmissionopportunity, the wireless device may perform an LBT procedure 3402 b,may determine that the PRACH 3404 b is idle, and/or may send/transmit apreamble via the PRACH 3404 b. The wireless device may monitor an RARduring an RAR window, for example, based on or in response tosending/transmitting the preamble via the PRACH 3404 b. The wirelessdevice may determine that the wireless device has not received an RARresponsive to the preamble sent via the PRACH 3404 b, for example, ifthe wireless device does not receive an RAR during the RAR window, failsto detect an RAR, and/or receives an RAR associated with anotherwireless device. The wireless device may determine whether to perform aretransmission of at least one preamble, for example, after determiningthat the wireless device has not received the RAR responsive to thepreamble sent via the PRACH 3404 b. The wireless device may determine aretransmission of at least one preamble, for example, during an n+1-th(re)transmission opportunity. The wireless device may switch to channelB. Channel B may be a channel to send/transmit one or more secondpreambles. Channel A and channel B may be different frequency bands,different BWPs, or different subbands in the same BWP. During an n+1-th(re)transmission opportunity, a wireless device may perform an LBTprocedure 3402 c, may determine that the PRACH 3404 c is not idle,and/or may determine to drop/cancel/delay/skip/abort a preambletransmission on the PRACH 3304 c.

FIG. 35 shows an example of channel switching. A base station maysend/transmit a message comprising configuration parameters indicatingone or more PRACHs in one or more channels (e.g., BWPs, subbands, orother time/frequency resources) for an RA procedure in an unlicensedband. A wireless device may switch between channels, for a preambletransmission, one or more times, for example, between retransmissionopportunities (e.g., between n-th (re)transmission opportunity and(n+1)-th (re)transmission opportunity), and/or within a (re)transmissionopportunity (e.g., within the n-th (re)transmission opportunity) in FIG.35. The wireless device may determine a channel switching based on oneor more LBT procedures performed on one or more PRACHs of the one ormore channels. The wireless device may perform the one or more LBTprocedures on different PRACHs (and/or different channels), for example,simultaneously or with a time gap. The wireless device may send/transmitat least one preamble via at least one of the one or the one or morePRACHs, for example, if the at least one of the one or the one or morePRACHs are determined to be idle.

As shown in FIG. 35, during an n-th (re)transmission opportunity, awireless device may perform an LBT procedure 3502 a on channel 1, maydetermine that the PRACH 3504 a is not idle, and/or may determine todrop/cancel/delay/skip/abort a preamble transmission on the PRACH 3504a. During the n-th (re)transmission opportunity, the wireless device mayperform an LBT procedure 3502 b on channel k, may determine that thePRACH 3504 b is not idle, and/or may determine todrop/cancel/delay/skip/abort a preamble transmission on the PRACH 3504b. During the n-th (re)transmission opportunity, the wireless device mayperform an LBT procedure 3502 c on channel 2, may determine that thePRACH 3504 c is idle, and/or may send/transmit a preamble via the PRACH3504 c. The wireless device may monitor an RAR during an RAR window, forexample, based on or in response to transmitting the preamble via thePRACH 3504 c. The wireless device may determine that the wireless devicehas not received an RAR responsive to the preamble sent via the PRACH3504 c, for example, if the wireless device does not receive an RARduring the RAR window, fails to detect an RAR, or receives an RARassociated with another wireless device. The wireless device maydetermine whether to perform a retransmission of at least one preamble,for example, after determining that the wireless device has not receivedthe RAR responsive to the preamble sent via the PRACH 3504 c. Thewireless device may determine a retransmission of at least one preamble,for example, during an n+1-th (re)transmission opportunity. The wirelessdevice may switch to channel 2 and may perform an LBT procedure 3502 d.The wireless device may determine that the PRACH 3504 d is not idle,and/or may determine to drop/cancel/delay/skip/abort a preambletransmission on the PRACH 3504 d.

A wireless device may manage (be configured with, control, determine,and/or update) one or counters for one or more channels. At least one ofthe one or more channels may comprise at least one BWP and/or at leastone subband. A wireless device may perform an LBT procedure before thewireless device sends/transmits data/a signal (e.g., a preamble) via oneof the one or more channels.

A counter (e.g., PREAMBLE_TRANSMISSION_COUNTER,PREAMBLE_RETRANSMISSION_COUNTER, and/or PREAMBLE_ATTEMPT_COUNTER) may beupdated (or set) per at least one channel (e.g., at least one BWP and/orat least one subband). The wireless device may update a transmissioncounter (e.g., PREAMBLE_TRANSMISSION_COUNTER) per channel (e.g.,PREAMBLE_TRANSMISSION_COUNTER # K, where K may indicate an identifier ofthe channel corresponding to index K). The wireless device may update aretransmission counter (e.g., PREAMBLE_RETRANSMISSION_COUNTER) perchannel (e.g., PREAMBLE_RETRANSMISSION_COUNTER # K, where K may indicatean identifier of the channel corresponding to index K). The wirelessdevice may update an attempt counter (e.g., PREAMBLE_ATTEMPT_COUNTER)per channel (e.g., PREAMBLE_ATTEMPT_COUNTER # K, where K may indicate anidentifier of the channel corresponding to index K).

The wireless device may manage per-channel counter(s), aggregatedcounter(s) and/or per-cell counter(s). A counter (e.g.,PREAMBLE_TRANSMISSION_COUNTER, PREAMBLE_RETRANSMISSION_COUNTER, and/orPREAMBLE_ATTEMPT_COUNTER) may aggregate the counter values ofper-channel counter(s). The counter (e.g.,PREAMBLE_TRANSMISSION_COUNTER, PREAMBLE_RETRANSMISSION_COUNTER, and/orPREAMBLE_ATTEMPT_COUNTER) may be a per-cell counter. A per-channelcounter may be at least one of PREAMBLE_TRANSMISSION_COUNTER updated perchannel (e.g., PREAMBLE_TRANSMISSION_COUNTER # K),PREAMBLE_RETRANSMISSION_COUNTER updated per channel (e.g.,PREAMBLE_RETRANSMISSION_COUNTER # K), and/or PREAMBLE_ATTEMPT_COUNTERupdated per channel (e.g., PREAMBLE_ATTEMPT_COUNTER # K), where K mayindicate an identifier of the channel corresponding to index K.

One or more counters configured for an RA procedure (e.g.,PREAMBLE_TRANSMISSION_COUNTER, PREAMBLE_RETRANSMISSION_COUNTER and/orPREAMBLE_ATTEMPT_COUNTER) may be implemented in one or more ways. Theone or more counters may start a counter operation from a predefinedvalue (e.g., zero) and/or a wireless device may set the one or morecounters to a predefined value (e.g., as an initialization). A counterdirection of at least one of the one or more counters may beincremental. A counter direction of at least one of the one or morecounters may be decremental. An incremental (or decremental) step (orunit) of at least one of the one or more counters may be predefined(e.g., by one or any other value).

A base station may send/transmit, to a wireless device, a messageindicating a request (e.g., UEInfomationRequest) for a RACH informationreport associated with an RA procedure in a cell. The RACH informationreport may comprise one or more fields indicating at least one of thefollowing: the quantity/number of preamble transmissions per cell, thenumber of preamble transmissions per channel (e.g., BWP, beam, SSB, SUL,NUL, or subband), the quantity/number of preamble transmission attemptsper cell, the quantity/number of preamble transmission attempts perchannel (e.g., BWP, beam, SSB, SUL, NUL, or subband), thequantity/number of preamble retransmissions per cell, thequantity/number of preamble retransmissions per channel (e.g., BWP,beam, SSB, SUL, NUL, or subband). The one or more fields may comprise atleast one of the following: PREAMBLE_TRANSMISSION_COUNTER aggregated percell, PREAMBLE_RETRANSMISSION_COUNTER aggregated per cell,PREAMBLE_ATTEMPT_COUNTER aggregated per cell, at least onePREAMBLE_TRANSMISSION_COUNTER updated per channel (e.g.,PREAMBLE_TRANSMISSION_COUNTER # K), at least onePREAMBLE_RETRANSMISSION_COUNTER updated per channel (e.g.,PREAMBLE_RETRANSMISSION_COUNTER # K), and/or at least onePREAMBLE_ATTEMPT_COUNTER updated per channel (e.g.,PREAMBLE_ATTEMPT_COUNTER # K, where K may indicate an identifier of thechannel corresponding to index K.

A first counter (e.g., PREAMBLE_ATTEMPT_COUNTER) (e.g., for a pluralityof channels) may be incremented by six, for example, based on the sixLBT procedures 3502 a, 3502 b, 3502 c, 3502 d, 3502 e, and 3502 f. Asecond counter (e.g., PREAMBLE_TRANSMISSION_COUNTER) (e.g., for theplurality of channels) may be incremented by one, for example, based onthe preamble transmission via the PRACH 3504 c. A third counter (e.g.,PREAMBLE_RETRANSMISSION_COUNTER) (e.g., for the plurality of channels)may be incremented by k, for example, based on the determination toallow the n+1-th (re)transmission opportunities for channel 1, channel2, . . . , and channel k. The first counter, the second counter, and/orthe third counter may be incremented by any value.

PREAMBLE_ATTEMPT_COUNTER #1 may be incremented by two, for example,based on the two LBT procedures 3502 a and 3502 f on channel 1.PREAMBLE_ATTEMPT_COUNTER #2 may be incremented by two, for example,based on the two LBT procedures 3502 c and 3502 d on channel 2.PREAMBLE_ATTEMPT_COUNTER # k may be incremented by two, for example,based on the two LBT procedures 3502 b and 3502 e on channel k.PREAMBLE_ATTEMPT_COUNTER (e.g., for the plurality of channels) may beincremented by six, for example, based on an aggregation of the countervalues of PREAMBLE_ATTEMPT_COUNTER #1, PREAMBLE_ATTEMPT_COUNTER #2, . .. , PREAMBLE_ATTEMPT_COUNTER # k (assuming k=3, or there are no LBTprocedures on channels 3, 4, . . . , and k−1).PREAMBLE_TRANSMISSION_COUNTER #2 may be incremented by one, for example,based on the preamble transmission via the PRACH 3504 c on channel 2.PREAMBLE_TRANSMISSION_COUNTER (e.g., for the plurality of channels) maybe incremented by one, for example, based on an aggregation of thecounter values of PREAMBLE_TRANSMISSION_COUNTER #1,PREAMBLE_TRANSMISSION_COUNTER #2, PREAMBLE_TRANSMISSION_COUNTER # k(assuming there are no other preamble transmissions on channels 1, 2, .. . , and k other than the preamble transmission via the PRACH 3504 c).PREAMBLE_RETRANSMISSION_COUNTER (e.g., for the plurality of channels)between the n-th (re)transmission opportunity and the n+1-the(re)transmission opportunity may be incremented by k, for example, basedon an aggregation of the counter values ofPREAMBLE_RETRANSMISSION_COUNTER #1, PREAMBLE_RETRANSMISSION_COUNTER #2,PREAMBLE_RETRANSMISSION_COUNTER # k.

A base station may indicate, in a request for a RACH information report,an aggregation level of one or more counters for an RA procedure in acell. The request may comprise one or more first fields indicatingwhether the wireless device report a cell-level counter and/or achannel-level counter. Values (e.g., predefined or configures values) ofthe one or more first fields may indicate whether the wireless devicereport a cell-level counter and/or a channel-level counter. A presenceor absence of the one or more first fields may indicate whether thewireless device report a cell-level counter and/or a channel-levelcounter.

A base station may indicate, in a request for a RACH information report,at least one particular type of a counter to be reported for an RAprocedure in a cell. The request may comprise one or more second fieldsindicating the at least one particular type. The at least one particulartype may comprise at least one of the following:PREAMBLE_TRANSMISSION_COUNTER, PREAMBLE_RETRANSMISSION_COUNTER,PREAMBLE_ATTEMPT_COUNTER, PREAMBLE_TRANSMISSION_COUNTER # K,PREAMBLE_RETRANSMISSION_COUNTER # K, and/or PREAMBLE_ATTEMPT_COUNTER #K, where K may indicate an identifier of the channel corresponding toindex K.

A base station may indicate, in a request for a RACH information report,at least one counter associated with a particular channel (e.g., a BWPand/or a subband) to be reported for an RA procedure in a cell. Therequest may comprise one or more third fields indicating the at leastone particular channel. The counter associated with the at least oneparticular channel may comprise at least one of the following:PREAMBLE_TRANSMISSION_COUNTER # K, PREAMBLE_RETRANSMISSION_COUNTER # K,and/or PREAMBLE_ATTEMPT_COUNTER # K, where K may indicate an identifierof the channel corresponding to index K.

Depending on an implementation, there may be one or more fourth fieldsin the request. The one or more fourth fields may indicate a combinationof RACH information (e.g., a type of counter, an aggregation level of acounter, and/or a counter associated with a channel). A wireless devicemay send (e.g., transmit), to a base station, a message (e.g.,UEInformationResponse) comprising a response to a request for a RACHinformation report. The response may comprise at least one of thefollowing: at least one per-cell counter that may be at least one ofPREAMBLE_TRANSMISSION_COUNTER, PREAMBLE_RETRANSMISSION_COUNTER, and/orPREAMBLE_ATTEMPT_COUNTER aggregate per-cell, and/or at least one aper-channel counter that may be at least one ofPREAMBLE_TRANSMISSION_COUNTER updated per channel (e.g.,PREAMBLE_TRANSMISSION_COUNTER # K), PREAMBLE_RETRANSMISSION_COUNTERupdated per channel (e.g., PREAMBLE_RETRANSMISSION_COUNTER # K), and/orPREAMBLE_ATTEMPT_COUNTER updated per channel (e.g.,PREAMBLE_ATTEMPT_COUNTER # K), where K may indicate an identifier of thechannel corresponding to index K.

FIG. 36 shows an example of triggering a RACH information report. Awireless device 110 may receive one or more DL reference signals (e.g.,SSBs or CSI-RSs) 3602 from a base station 120. The wireless device 110may initiate an RA procedure. The wireless device 110 may attempt tosend/transmit one or more preambles 3604 via one or more PRACHs in oneor more channels (e.g., BWPs, beams, SSBs, SULs, NULs, and/or subbands).The wireless device 110 may receive a response 3606, based on which thewireless device 110 may determine that the RA procedure is completedsuccessfully. The wireless device 110 may receive a message comprising arequest for a RACH information report 3608. The request 3608 mayindicate one or more aggregation levels of one or more counters, one ormore types of the one or more counters, and/or one or more channels(e.g., BWPs, beam, SSBs, SULs, NULs, and/or subbands) associated withthe one or more counters. The wireless device 110 may transmit a messagecomprising a response 3610 that comprises/indicates the RACH informationreport.

FIG. 37 show an example of communicating RACH information. A basestation may send/transmit, to a wireless device, a message comprising arequest (e.g., UEInformationRequest). The request (e.g.,UEInformationRequest) may be a command used by the base station toretrieve information from the wireless device (e.g., signaling radiobearer: SRB1). An example format of request (e.g., UEInformationRequest) may be as below:

UEInformationRequest ::= SEQUENCE { rach-ReportReq BOOLEAN,rlf-ReportReq BOOLEAN, nonCriticalExtension UEInformationRequest}.

An indication (e.g., rach-ReportReq) may be used to indicate whether thewireless device reports RACH information. A request (e.g.,UEInformationRequest) may comprise one or more aggregation levels of oneor more counters, one or more types of the one or more counters, and/orone or more channels (e.g., BWPs, beams, SSBs, SULs, NULs, and/orsubbands) associated with the one or more counters.

Based on or in response to receiving the request (e.g.,UEInformationRequest) message, the wireless device may perform one ormore of the following: if rach-ReportReq is set to true, setting thecontents of the rach-Report in the UEInformationResponse message asfollows: (1) setting the numberOfPreamblesSent to indicate the number ofpreambles sent by a MAC layer for the last successfully completed randomaccess procedure; and/or (2) a) if contention resolution was notsuccessful for at least one of the transmitted preambles for the lastsuccessfully completed random access procedure: setting thecontentionDetected to true; or b) else: setting the contentionDetectedto false. The wireless device may send/transmit, to the base station, aresponse (e.g., UEInformationResponse) message comprising a quantity ofpreambles sent (e.g., numberOfPreamblesSent) and/or an indication ofcontention detection (e.g., contentionDetected). The parameter for aquantity of preambles sent (e.g., numberOfPreamblesSent) may comprise atleast one of: the quantity/number of preamble transmissions per channel(e.g., BWP, SSB, SUL, NUL, beam, and/or subband), the quantity/number ofpreamble transmissions in the cell, the quantity/number of preambletransmission attempts per channel (e.g., BWP, SSB, SUL, NUL, beam,and/or subband), the quantity/number of preamble transmission attemptsin the cell, the quantity/number of preamble retransmissions per channel(e.g., BWP, SSB, SUL, NUL, beam, and/or subband), and/or thequantity/number of preamble retransmissions in the cell.

A base station may determine one or more BI values of one or morechannels (e.g., BWPs, SSBs, SULs, NULs, beams, or subbands), forexample, based on the response (e.g., UEInformationResponse). One ormore per-channel (e.g., per-BWP, per-beam, per-SSB, per-uplink, and/orper-subband) counters may indicate a level of congestion in therespective channel(s) (e.g., BWP(s), SSB(s), SUL(s), NUL(s), beam(s),and/or subband(s)). A base station may determine a first BI valueassociated with a first channel (e.g., a first BWP, a first SSB, a firstSUL, a first NUL, a first beam, and/or a first subband), for example,based on a first counter associated with the first channel (e.g., thefirst BWP, the first SSB, the first SUL, the first NUL, the first beam,and/or the first subband). The first counter may be any of per-channelcounter (e.g., PREAMBLE_TRANSMISSION_COUNTER # K,PREAMBLE_RETRANSMISSION_COUNTER # K, PREAMBLE_ATTEMPT_COUNTER # K, whereK may indicate (or may be associated with) the first channelcorresponding to index K).

FIG. 38 shows an example method of a random access operation. At step3802, a base station may send (e.g., transmit) one or more configurationparameters of one or more channels (e.g., BWPs, SSBs, SULs, NULs, beams,and/or subbands). The one or more configuration parameters may indicateone or more time/frequency resources of one or more channels for arandom access preamble transmission, one or more random accessconfiguration parameters associated with the one or more channels, etc.At step 3804, the base station may receive, from a wireless device, atleast one preamble via one of the one or more channels. At step 3806,the base station may send/transmit, to the wireless device and based onthe at least one preamble, a response indicating that the random accessprocedure is successful. At step 3808, the base station maysend/transmit, to the wireless device, a RACH information request. Theresponse indicating that the random access procedure is successful maycomprise the RACH information request. At step 3810, the base stationmay receive, from the wireless device, a response to the RACHinformation request. The response to the RACH information request maycomprise one or more timers associated with random access. The one ormore timers may comprise one or more per-cell timers, one or moreper-channel timers, one or more per-BWP timers, one or more per-beamtimers, one or more per-SSB timers, per-uplink timers, and/or one ormore per-subband timers. At step 3812, the base station may determinewhether at least one of the one or more channels need to be updatedbased on the response to the RACH information request. The base stationmay return to step 3802, for example, if the base station determinesthat configuration(s) for the one or more channels do not need to beupdated. At step 3814, the base station may update, based on theresponse to the RACH information request, the one or more configurationparameters of the one or more channels, for example, if the base stationdetermines that at least one configuration for the one or more channelsneeds to be updated.

FIG. 39 shows an example method of a random access operation. At step3902, a wireless device may determine to initiate a random accessprocedure. The wireless device may determine one or more channels toperform the random access procedure. At step 3904, the wireless devicemay perform an LBT procedure for one or more preamble transmissions viaat least one of the one or more channels. The LBT procedure may beomitted for one or more preamble transmissions via one or more firstchannels (e.g., licensed bands). The LBT procedure may be performed forone or more preamble transmissions via one or more second channels(e.g., unlicensed bands). At step 3906, the wireless device maydetermine whether at least one channel (e.g., at least one of the one ormore second channels) is idle, for example, based on the LBT procedure.The wireless device may return to step 3904, for example, if it isdetermined that there is no idle channel for a preamble transmission. Atstep 3908, the wireless device may send/transmit, via the at least onechannel that is determined to be idle, one or more preambles, forexample, if it is determined that there is at least one idle channel fora preamble transmission. At step 3910, the wireless device may determinewhether a response indicating that the random access procedure issuccessfully completed is received. The wireless device may return tostep 3904, for example, if the wireless device determines that theresponse indicating that the random access procedure is successfullycompleted has not been received. At step 3912, the wireless device mayreceive, from a base station, a RACH information request, for example,after the random access procedure being successfully completed. At step3914, the wireless device may send/transmit, to the base station, aresponse to the RACH information request.

A wireless device may receive, from a base station, a first messagecomprising a request to report random access information of a cell. Thewireless device may send/transmit, to the base station, a second messagecomprising a response indicating the random access information. The cellmay comprise one or more UL BWPs. The one or more UL BWPs may compriseat least one PRACH. A UL BWP may comprise a plurality of subbands. Theresponse may comprise at least one of the following: the number ofpreamble transmissions performed via the cell; the number of preambletransmission attempts (or LBT) performed on the cell. The response maycomprise at least one of the following: a second counter valueindicating the number/quantity of times that the wireless devicedetermines a retransmission of at least one preamble, for example, afteror in response to an RAR reception being unsuccessful and/or acontention resolution being unsuccessful; and/or a second counter valueindicating the number/quantity of times that the wireless devicedetermines an RAR reception being unsuccessful and/or a contentionresolution being unsuccessful. The cell may comprise one or more ULBWPs. The response may comprise at least one of the following: thenumber/quantity of preamble transmissions performed via at least one ofthe one or more BWPs; and/or the number/quantity of preambletransmission attempts (e.g., LBT) associated with at least one of theone or more BWPs. The response may comprise at least one of thefollowing: a second counter value indicating the number of times thatthe wireless device determines a retransmission of at least onepreamble, for example, after or in response to an RAR reception beingunsuccessful and/or a contention resolution being unsuccessful; and/or asecond counter value indicating the number of times that the wirelessdevice determines an RAR reception being unsuccessful and/or acontention resolution being unsuccessful. The request may comprise anindicator to report random access information per BWP. A presence of afirst field may be the indicator. The wireless device may transmit, tothe base station, one or more preambles for the random access procedure.The wireless device may determine that the random access procedure issuccessfully completed. The wireless device may count at least one ofthe following: the number/quantity of preamble transmissions performedvia the cell; the number/quantity of preamble transmission attempts(e.g., LBT) associated with the cell; the number/quantity of preambletransmissions performed on at least one of the one or more BWPs; thenumber/quantity of preamble transmission attempts (e.g., LBT) associatedwith at least one of the one or more BWPs; the number of preambletransmission attempts (e.g., LBT) associated with at least one of theone or more BWPs; a second counter value indicating the number of timesthat the wireless device determines a retransmission of at least onepreamble, for example, after or in response to an RAR reception beingunsuccessful and/or a contention resolution being unsuccessful; and/or asecond counter value indicating the number of times that the wirelessdevice determines an RAR reception being unsuccessful and/or acontention resolution being unsuccessful.

A wireless device may transmit, to a base station, one or more preamblesfor a random access procedure. The wireless device may determine thatthe random access procedure is successfully completed. The wirelessdevice may receive a first message comprising a random access reportrequest for a plurality of subbands in a cell. The wireless device maytransmit, to the base station, a second message comprising a randomaccess report indicating a first number/quantity of the one or morepreambles transmitted via the at least one of the plurality of subbands,for example, after or in response to receiving the first message. Thewireless device may receive a random access response comprising anuplink grant. The random access response may identify one of the one ormore preambles. The wireless device may transmit, via one or moreresources indicated by the uplink grant, a transport block. The wirelessdevice may determine that the random access procedure is unsuccessfullycompleted, for example, based on not receiving a contention resolutionmessage. The wireless device may increment a random access contentioncount. The random access report may indicate a second number/quantity ofrandom access contentions detected on the at least one of a plurality ofsubbands. The second number/quantity of random access contentionsdetermined based on the random access contention count. The randomaccess report may indicate a third number/quantity of channel accessprocedures performed via the at least one of a plurality of subbands.

A wireless device may receive, from a base station, a first messagecomprising a random access report request for a plurality of subbands ina cell. The wireless device may transmit, to the base station, a secondmessage, for example, after or in response to receiving the firstmessage. The second message may comprise a response comprising at leastone of the following: the number/quantity of one or more preamblestransmitted by the wireless device for the cell; the number/quantity ofrandom access contentions detected by the wireless device for the cell;the number/quantity of one or more channel access procedures performedby the wireless device for the cell; the number/quantity of one or morepreamble transmissions via at least one of a plurality of subbands. Thenumber/quantity of the one or more preambles may be counted during thelast successfully completed random access procedure. The number/quantityof the one or more preambles may be determined based on a preambletransmission counter. The wireless device may increment (e.g., by one acounter counting the number/quantity of random access contentions, forexample, if contention resolution was not successful for the lastsuccessfully completed random access procedure.

A base station may transmit, to one or more first wireless device, oneor more first messages comprising at least one request to report randomaccess information of a cell (e.g., of one or more BWPs in a cell). Thebase station may receive, from at least one of the first wirelessdevice, a second message comprising a response comprising the randomaccess information, for example, after or in response to the at leastone request. The base station may transmit, to one or more secondwireless device, at least one RAR comprising a plurality of backoffindicators. Each of the plurality of backoff indicators may indicate abackoff time of one of one or more BWPs in the cell. The base stationmay determine the plurality of backoff indicators at least based on therandom access information. The random access information may indicate atleast one of the following: the number/quantity of preambletransmissions performed via the cell; the number/quantity of preambletransmission attempts (e.g., LBT) associated with the cell; thenumber/quantity of preamble transmissions performed via at least one ofthe one or more BWPs; the number/quantity of preamble transmissionattempts (e.g., LBT) associated with at least one of the one or moreBWPs; the number/quantity of preamble transmission attempts (e.g., LBT)associated with at least one of the one or more BWPs; a second countervalue indicating the number/quantity of times that the wireless devicedetermines a retransmission of at least one preamble, for example, afteror in response to an RAR reception being unsuccessful and/or acontention resolution being unsuccessful; and/or a second counter valueindicating the number/quantity of times that the wireless devicedetermines an RAR reception being unsuccessful and/or a contentionresolution being unsuccessful.

A base station may transmit, to one or more first wireless device, oneor more first messages comprising at least one request to report randomaccess information of an uplink carrier. The uplink carrier may comprisea plurality of BWPs comprising a first BWP and a second BWP. The basestation may receive, from at least one of the one or more first wirelessdevice, a second message comprising a response comprising the randomaccess information, for example, after or in response to the at leastone request. The random access information may comprise: first randomaccess information of the first BWP; and/or second random accessinformation of the second BWP. The base station may transmit, to one ormore second wireless device: at least one first RAR via the first BWP;and/or at least one second RAR via the second BWP. The at least onefirst RAR may comprise a first backoff indicator determined based on thefirst random access information. The at least one second RAR maycomprise a second backoff indicator determined based on the secondrandom access information.

A base station may receive, from a wireless device, at least onepreamble associated with random access (e.g., based on one or morepreamble transmission attempts in a cell). The cell may be an unlicensedcell. The cell may comprise an unlicensed band and/or an unlicensedsub-band. The cell may comprise a plurality of sub-bands (e.g., aplurality of sub-bands of a BWP). The base station may send/transmit, tothe wireless device, a report request associated with the random access.The base station may receive, from the wireless device and based on thereport request, a response to the report request. The response maycomprise at least one of: a first indication (e.g., a first indicator)associated with a quantity/number of preamble transmissions via a firstsub-band of a plurality of sub-bands of the cell; and/or a secondindication associated with a quantity/number of preamble transmissionattempts associated with the first sub-band. The second indication mayindicate at least one of: the quantity of the preamble transmissionattempts associated with the first sub-band; and/or a quantity ofpreamble transmission failures associated with the first sub-band. Apreamble transmission failure may comprise at least one of: dropping,canceling, delaying, skipping, or aborting a preamble transmission. Thewireless device may determine, based on an identifier associated withthe first sub-band, the response comprising the first indication and thesecond indication. The wireless device may determine, based on theidentifier, a transmission of the response comprising the firstindication and the second indication. The report request may comprisethe identifier. The response may comprise a third indication associatedwith a quantity/number of preamble transmissions via a second sub-bandof the plurality of sub-bands of the cell. The response may comprise afourth indication associated with a quantity/number of preambletransmission attempts associated with the second sub-band. The reportrequest may comprise a second identifier associated with the secondsub-band. The wireless device may determine, based on the secondidentifier, the response comprising the third indication and the fourthindication. The wireless device may determine, based on the secondidentifier, a transmission of the response comprising the thirdindication and the fourth indication. The report request may comprisethe second identifier. The first sub-band and/or the second sub-band maybe in an unlicensed band. The response may indicate a first totalquantity/number of preamble transmissions via the plurality of sub-bandsof the cell. The response may indicate a second total quantity/number ofpreamble transmission attempts associated with the plurality ofsub-bands in the cell. The report request may comprise an indication forrequesting the first total quantity/number and/or the second totalquantity/number. The wireless device may determine, based on theindication for requesting the first total quantity/number and/or thesecond total quantity/number, a transmission of the response indicatingthe first total quantity/number and/or the second total quantity/number.The first total quantity/number may be an aggregated quantity/number ofone or more preamble transmissions via the cell (e.g., via the pluralityof sub-bands of the cell). The first total quantity/number may bedetermined based on one or more preamble transmission counter values(e.g., a preamble transmission counter value of the cell). The wirelessdevice may increment the one or more preamble transmission countervalues, for example, based on one or more preamble transmissions duringa random access procedure. The second total quantity/number may be anaggregated quantity/number of one or more preamble transmission attemptsassociated with the cell (e.g., the plurality of channels of the cell).The second total quantity/number may be determined, for example, basedon one or more preamble transmission attempt counter values (e.g., apreamble transmission attempt counter value of the cell). The wirelessdevice may determine, based on an occupancy status associated with arandom access occasion of the first sub-band. The wireless device mayincrement, after determining the occupancy status, a preambletransmission attempt counter value associated with the first sub-band.The wireless device may determine the occupancy status, for example,based on an LBT procedure. The quantity/number of preamble transmissionsvia the first sub-band may be determined, for example, based on a firstpreamble transmission counter value associated with the first sub-band.The first preamble transmission counter value may be incremented, forexample, after or in response to transmitting a preamble via the firstsub-band. The quantity/number of preamble transmission attemptsassociated with the first sub-band may be determined, for example, basedon a first preamble transmission attempt counter value associated withthe first sub-band. The first preamble transmission attempt countervalue may be incremented, for example, after or in response to an LBTprocedure associated with the first sub-band (e.g., an LBT procedureperformed, for a preamble transmission, indicating a status of the firstsub-band). The wireless device may determine, based on a first occupancystatus associated with a first random access occasion of the firstsub-band, a first preamble transmission failure associated with thefirst random access occasion. The wireless device may determine, basedon a second occupancy status associated with a second random accessoccasion of a second sub-band of the plurality of sub-bands, a secondpreamble transmission failure associated with the second random accessoccasion. The wireless device may increment, based on determining thefirst occupancy status and the second occupancy status, at least onepreamble transmission attempt counter value (e.g., the preambletransmission attempt counter value of the cell, the first preambletransmission attempt counter value associated with the first sub-band, asecond preamble transmission attempt counter value associated with thesecond sub-band, etc.). The preamble transmission attempt counter valueof the cell may be an aggregated preamble transmission attempt countervalue associated with the plurality of sub-bands. The base station maysend/transmit, to the wireless device, a control message indicating atleast one changed configuration parameter associated with at least oneof the plurality of sub-bands. The control message may besent/transmitted, for example, after transmitting the response. Thewireless device may change, based on the at least one changedconfiguration parameter, at least one preamble transmission timingassociated with the at least one of the plurality of sub-bands. The atleast one changed configuration parameter may comprise at least onerandom access configuration parameters. The at least one changedconfiguration parameter may comprise one or more PRACH occasions, one ormore backoff indicators (BIs), random access types (e.g., acontention-based random access or a contention-free random access), etc.

A base station may send/transmit, to a wireless device, a report requestassociated with random access (e.g., associated with a cell). Thewireless device may determine, based on the report request, anidentifier associated with a first channel of a plurality of channels ofa cell. The base station may receive, from the wireless device and basedon the report request and the identifier, a response. The response maycomprise at least one of: a first indication associated with a quantityof preamble transmissions via the first channel; and a second indicationassociated with a quantity of preamble transmission attempts associatedwith the first channel. The first channel may comprise a first sub-bandof a plurality of sub-bands of the cell. The base station may receive,from the wireless device, at least one preamble associated with therandom access. The wireless device may determine, based on theidentifier, the response comprising the first indication and the secondindication. The base station may receive, after completing the randomaccess, the report request. The response may indicate at least one of: afirst total quantity of preamble transmissions via the plurality ofchannels of the cell; and/or a second total quantity of preambletransmission attempts associated with the plurality of channels of thecell. The wireless device may determine, based on a first occupancystatus associated with a first random access occasion of the firstchannel, a first preamble transmission failure associated with the firstrandom access occasion. The wireless device may determine, based on asecond occupancy status associated with a second random access occasionof a second channel of the plurality of channels, a second preambletransmission failure associated with the second random access occasion.The wireless device may increment, based on determining the firstoccupancy status and the second occupancy status, at least one preambletransmission attempt counter value.

A base station may receive, from a wireless device, at least onepreamble for random access (e.g., associated with a cell). The basestation may send/transmit, to the wireless device, a report requestassociated with the random access. The base station may receive, basedon the report request, a response. The response may comprise at leastone of: a first indication associated with a quantity of preambletransmissions via a first sub-band of a plurality of sub-bands of thecell; and/or a second indication associated with a quantity of preambletransmissions via a second sub-band of the plurality of sub-bands of thecell. The response may comprise a third indication associated with aquantity of preamble transmission attempts associated with the firstsub-band. The response may comprise a fourth indication associated witha quantity of preamble transmission attempts associated with the secondsub-band. The response may indicate a first total quantity of preambletransmissions via the plurality of sub-bands of the cell. The responsemay indicate a second total quantity of preamble transmission attemptsassociated with the plurality of channels of the cell. The wirelessdevice may determine, based on at least one identifier associated withthe first sub-band and/or with the second sub-band, the responsecomprising the first indication and/or the second indication. The reportrequest may comprise the at least one identifier. The wireless devicedetermine, based on a first occupancy status associated with a firstrandom access occasion of the first sub-band, a first preambletransmission failure associated with the first random access occasion.The wireless device may determine, based on a second occupancy statusassociated with a second random access occasion of the second sub-band,a second preamble transmission failure associated with the second randomaccess occasion. The wireless device may increment, based on determiningthe first occupancy status and the second occupancy status, at least onepreamble transmission attempt counter value.

FIG. 40 shows example elements of a computing device that may be used toimplement any of the various devices described herein, including, e.g.,the base station 120A and/or 120B, the wireless device 110 (e.g., 110Aand/or 110B), or any other base station, wireless device, or computingdevice described herein. The computing device 4000 may include one ormore processors 4001, which may execute instructions stored in therandom-access memory (RAM) 4103, the removable media 4004 (such as aUniversal Serial Bus (USB) drive, compact disk (CD) or digital versatiledisk (DVD), or floppy disk drive), or any other desired storage medium.Instructions may also be stored in an attached (or internal) hard drive4005. The computing device 4000 may also include a security processor(not shown), which may execute instructions of one or more computerprograms to monitor the processes executing on the processor 4001 andany process that requests access to any hardware and/or softwarecomponents of the computing device 4000 (e.g., ROM 4002, RAM 4003, theremovable media 4004, the hard drive 4005, the device controller 4007, anetwork interface 4009, a GPS 4011, a Bluetooth interface 4012, a WiFiinterface 4013, etc.). The computing device 4000 may include one or moreoutput devices, such as the display 4006 (e.g., a screen, a displaydevice, a monitor, a television, etc.), and may include one or moreoutput device controllers 4007, such as a video processor. There mayalso be one or more user input devices 4008, such as a remote control,keyboard, mouse, touch screen, microphone, etc. The computing device4000 may also include one or more network interfaces, such as a networkinterface 4009, which may be a wired interface, a wireless interface, ora combination of the two. The network interface 4009 may provide aninterface for the computing device 4000 to communicate with a network4010 (e.g., a RAN, or any other network). The network interface 4009 mayinclude a modem (e.g., a cable modem), and the external network 4010 mayinclude communication links, an external network, an in-home network, aprovider's wireless, coaxial, fiber, or hybrid fiber/coaxialdistribution system (e.g., a DOCSIS network), or any other desirednetwork. Additionally, the computing device 4000 may include alocation-detecting device, such as a global positioning system (GPS)microprocessor 4011, which may be configured to receive and processglobal positioning signals and determine, with possible assistance froman external server and antenna, a geographic position of the computingdevice 4000.

The example in FIG. 40 may be a hardware configuration, although thecomponents shown may be implemented as software as well. Modificationsmay be made to add, remove, combine, divide, etc. components of thecomputing device 4000 as desired. Additionally, the components may beimplemented using basic computing devices and components, and the samecomponents (e.g., processor 4001, ROM storage 4002, display 4006, etc.)may be used to implement any of the other computing devices andcomponents described herein. For example, the various componentsdescribed herein may be implemented using computing devices havingcomponents such as a processor executing computer-executableinstructions stored on a computer-readable medium, as shown in FIG. 40.Some or all of the entities described herein may be software based, andmay co-exist in a common physical platform (e.g., a requesting entitymay be a separate software process and program from a dependent entity,both of which may be executed as software on a common computing device).

The disclosed mechanisms herein may be performed if certain criteria aremet, for example, in a wireless device, a base station, a radioenvironment, a network, a combination of the above, and/or the like.Example criteria may be based on, for example, wireless device and/ornetwork node configurations, traffic load, initial system set up, packetsizes, traffic characteristics, a combination of the above, and/or thelike. If the one or more criteria are met, various examples may be used.It may be possible to implement examples that selectively implementdisclosed protocols.

A base station may communicate with a mix of wireless devices. Wirelessdevices and/or base stations may support multiple technologies, and/ormultiple releases of the same technology. Wireless devices may have somespecific capability(ies) depending on wireless device category and/orcapability(ies). A base station may comprise multiple sectors. A basestation communicating with a plurality of wireless devices may refer tobase station communicating with a subset of the total wireless devicesin a coverage area. Wireless devices referred to herein may correspondto a plurality of wireless devices of a particular LTE or 5G releasewith a given capability and in a given sector of a base station. Aplurality of wireless devices may refer to a selected plurality ofwireless devices, and/or a subset of total wireless devices in acoverage area. Such devices may operate, function, and/or perform basedon or according to drawings and/or descriptions herein, and/or the like.There may be a plurality of base stations or a plurality of wirelessdevices in a coverage area that may not comply with the disclosedmethods, for example, because those wireless devices and/or basestations perform based on older releases of LTE or 5G technology.

One or more features described herein may be implemented in acomputer-usable data and/or computer-executable instructions, such as inone or more program modules, executed by one or more computers or otherdevices. Generally, program modules include routines, programs, objects,components, data structures, etc. that perform particular tasks orimplement particular abstract data types when executed by a processor ina computer or other data processing device. The computer executableinstructions may be stored on one or more computer readable media suchas a hard disk, optical disk, removable storage media, solid statememory, RAM, etc. The functionality of the program modules may becombined or distributed as desired. The functionality may be implementedin whole or in part in firmware or hardware equivalents such asintegrated circuits, field programmable gate arrays (FPGA), and thelike. Particular data structures may be used to more effectivelyimplement one or more features described herein, and such datastructures are contemplated within the scope of computer executableinstructions and computer-usable data described herein.

Many of the elements in examples may be implemented as modules. A modulemay be an isolatable element that performs a defined function and has adefined interface to other elements. The modules may be implemented inhardware, software in combination with hardware, firmware, wetware(i.e., hardware with a biological element) or a combination thereof, allof which may be behaviorally equivalent. For example, modules may beimplemented as a software routine written in a computer languageconfigured to be executed by a hardware machine (such as C, C++,Fortran, Java, Basic, Matlab or the like) or a modeling/simulationprogram such as Simulink, Stateflow, GNU Octave, or Lab VIEWMathScript.Additionally or alternatively, it may be possible to implement modulesusing physical hardware that incorporates discrete or programmableanalog, digital and/or quantum hardware. Examples of programmablehardware may comprise: computers, microcontrollers, microprocessors,application-specific integrated circuits (ASICs); field programmablegate arrays (FPGAs); and complex programmable logic devices (CPLDs).Computers, microcontrollers, and microprocessors may be programmed usinglanguages such as assembly, C, C++ or the like. FPGAs, ASICs, and CPLDsmay be programmed using hardware description languages (HDL), such asVHSIC hardware description language (VHDL) or Verilog, which mayconfigure connections between internal hardware modules with lesserfunctionality on a programmable device. The above-mentioned technologiesmay be used in combination to achieve the result of a functional module.

A non-transitory tangible computer readable media may compriseinstructions executable by one or more processors configured to causeoperations of multi-carrier communications described herein. An articleof manufacture may comprise a non-transitory tangible computer readablemachine-accessible medium having instructions encoded thereon forenabling programmable hardware to cause a device (e.g., a wirelessdevice, wireless communicator, a wireless device, a base station, andthe like) to allow operation of multi-carrier communications describedherein. The device, or one or more devices such as in a system, mayinclude one or more processors, memory, interfaces, and/or the like.Other examples may comprise communication networks comprising devicessuch as base stations, wireless devices or user equipment (wirelessdevice), servers, switches, antennas, and/or the like. A network maycomprise any wireless technology, including but not limited to,cellular, wireless, WiFi, 4G, 5G, any generation of 3GPP or othercellular standard or recommendation, wireless local area networks,wireless personal area networks, wireless ad hoc networks, wirelessmetropolitan area networks, wireless wide area networks, global areanetworks, space networks, and any other network using wirelesscommunications. Any device (e.g., a wireless device, a base station, orany other device) or combination of devices may be used to perform anycombination of one or more of steps described herein, including, forexample, any complementary step or steps of one or more of the abovesteps.

Although examples are described above, features and/or steps of thoseexamples may be combined, divided, omitted, rearranged, revised, and/oraugmented in any desired manner Various alterations, modifications, andimprovements will readily occur to those skilled in the art. Suchalterations, modifications, and improvements are intended to be part ofthis description, though not expressly stated herein, and are intendedto be within the spirit and scope of the descriptions herein.Accordingly, the foregoing description is by way of example only, and isnot limiting.

What is claimed is:
 1. A method comprising: transmitting, by a wirelessdevice to a base station, at least one preamble associated with randomaccess; receiving a report request associated with the random access;and transmitting, based on the report request, a response comprising: afirst indication associated with a quantity of preamble transmissionsvia a first sub-band of a plurality of sub-bands of a cell; and a secondindication associated with a quantity of preamble transmission attemptsassociated with the first sub-band.
 2. The method of claim 1, whereinthe second indication indicates at least one of: the quantity of thepreamble transmission attempts associated with the first sub-band; or aquantity of preamble transmission failures associated with the firstsub-band, wherein a preamble transmission failure comprises at least oneof: dropping, canceling, delaying, skipping, or aborting a preambletransmission.
 3. The method of claim 1, further comprising determining,based on an identifier associated with the first sub-band, the responsecomprising the first indication and the second indication, wherein thereport request comprises the identifier.
 4. The method of claim 1,wherein the response further comprises: a third indication associatedwith a quantity of preamble transmissions via a second sub-band of theplurality of sub-bands of the cell; and a fourth indication associatedwith a quantity of preamble transmission attempts associated with thesecond sub-band.
 5. The method of claim 1, wherein the response furtherindicates: a first total quantity of preamble transmissions via theplurality of sub-bands of the cell; and a second total quantity ofpreamble transmission attempts associated with the plurality ofsub-bands of the cell.
 6. The method of claim 5, wherein the secondtotal quantity of preamble transmission attempts is determined based onat least one preamble transmission attempt counter value.
 7. The methodof claim 1, further comprising: determining an occupancy statusassociated with a random access occasion of the first sub-band; andincrementing, after determining the occupancy status, a preambletransmission attempt counter value associated with the first sub-band.8. The method of claim 1, further comprising: determining, based on afirst occupancy status associated with a first random access occasion ofthe first sub-band, a first preamble transmission failure associatedwith the first random access occasion; determining, based on a secondoccupancy status associated with a second random access occasion of asecond sub-band of the plurality of sub-bands, a second preambletransmission failure associated with the second random access occasion;and incrementing, based on determining the first occupancy status andthe second occupancy status, at least one preamble transmission attemptcounter value.
 9. The method of claim 8, wherein the at least onepreamble transmission attempt counter value comprises at least one of: afirst preamble transmission attempt counter value associated with thefirst sub-band; a second preamble transmission attempt counter valueassociated with the second sub-band; or an aggregated preambletransmission attempt counter value associated with the plurality ofsub-bands.
 10. A method comprising: receiving, by a wireless device froma base station, a report request associated with random access;determining, based on the report request, an identifier associated witha first channel of a plurality of channels of a cell; and transmitting,based on the report request and the identifier, a response comprising: afirst indication associated with a quantity of preamble transmissionsvia the first channel; and a second indication associated with aquantity of preamble transmission attempts associated with the firstchannel.
 11. The method of claim 10, wherein the first channel comprisesa first sub-band of a plurality of sub-bands of the cell.
 12. The methodof claim 10, further comprising: transmitting, by the wireless device tothe base station, at least one preamble associated with the randomaccess; and determining, based on the identifier, the responsecomprising the first indication and the second indication.
 13. Themethod of claim 10, wherein the receiving the report request comprisesreceiving, after completing the random access, the report request. 14.The method of claim 10, wherein the response further indicates: a firsttotal quantity of preamble transmissions via the plurality of channelsof the cell; and a second total quantity of preamble transmissionattempts associated with the plurality of channels of the cell.
 15. Themethod of claim 10, further comprising: determining, based on a firstoccupancy status associated with a first random access occasion of thefirst channel, a first preamble transmission failure associated with thefirst random access occasion; determining, based on a second occupancystatus associated with a second random access occasion of a secondchannel of the plurality of channels, a second preamble transmissionfailure associated with the second random access occasion; andincrementing, based on determining the first occupancy status and thesecond occupancy status, at least one preamble transmission attemptcounter value.
 16. A method comprising: transmitting, by a wirelessdevice to a base station, at least one preamble associated with randomaccess; receiving a report request associated with the random access;and transmitting, based on the report request, a response comprising: afirst indication associated with a quantity of preamble transmissionsvia a first sub-band of a plurality of sub-bands of a cell; and a secondindication associated with a quantity of preamble transmissions via asecond sub-band of the plurality of sub-bands of the cell.
 17. Themethod of claim 16, wherein the response further comprises: a thirdindication associated with a quantity of preamble transmission attemptsassociated with the first sub-band; and a fourth indication associatedwith a quantity of preamble transmission attempts associated with thesecond sub-band.
 18. The method of claim 16, wherein the responsefurther indicates: a first total quantity of preamble transmissions viathe plurality of sub-bands of the cell; and a second total quantity ofpreamble transmission attempts associated with the plurality ofsub-bands of the cell.
 19. The method of claim 16, further comprisingdetermining, based on at least one identifier associated with the firstsub-band and with the second sub-band, the response comprising the firstindication and the second indication, wherein the report requestcomprises the at least one identifier.
 20. The method of claim 16,further comprising: determining, based on a first occupancy statusassociated with a first random access occasion of the first sub-band, afirst preamble transmission failure associated with the first randomaccess occasion; determining, based on a second occupancy statusassociated with a second random access occasion of the second sub-band,a second preamble transmission failure associated with the second randomaccess occasion; and incrementing, based on determining the firstoccupancy status and the second occupancy status, at least one preambletransmission attempt counter value.